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Revision History for A114176

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Triangle, read by rows, where the g.f. of column n, C_n(x), equals the g.f. of row n, R_n(x), divided by (1-x)^(n+1)*(1-x^2)^n, for n>=0; e.g., C_n(x) = R_n(x)/(1-x)^(n+1)/(1-x^2)^n.
(history; published version)
#6 by Charles R Greathouse IV at Tue Jun 13 23:40:22 EDT 2017
STATUS

editing

approved

#5 by Charles R Greathouse IV at Tue Jun 13 23:40:19 EDT 2017
PROG

(PARI) {T(n, k)=if(n<k || k<0, 0, if(n==k || k==0, 1, polcoeff(sum(j=0, k, T(k, j)*x^j)/(1-x+x*O(x^(n-k)))^(k+1)/(1-x^2)^k, n-k)))}

STATUS

approved

editing

#4 by Russ Cox at Fri Mar 30 18:36:52 EDT 2012
FORMULA

T(n,k) = Sum_{j=0..k} T(k,j)*Sum_{i=0..n-j-k} (-1)^(n-i-j-k)*C(2k+i,i)*C(n-i-j-1,n-i-j-k) for n>k with T(n,n)=1 for n>=0. - _Paul D. Hanna (pauldhanna(AT)juno.com), _, Jun 21 2006

PROG

(PARI) {T(n, k)=if(n==k, 1, sum(j=0, k, T(k, j)*sum(i=0, n-j-k, (-1)^(n-i-j-k)*binomial(2*k+i, i)*binomial(n-i-j-1, n-i-j-k))))} - _Paul D. Hanna (pauldhanna(AT)juno.com), _, Jun 21 2006

AUTHOR

_Paul D. Hanna (pauldhanna(AT)juno.com), _, Nov 15 2005

Discussion
Fri Mar 30
18:36
OEIS Server: https://oeis.org/edit/global/213
#3 by N. J. A. Sloane at Sat Nov 10 03:00:00 EST 2007
FORMULA

T(n,k) = Sum_{j=0..k} T(k,j)*Sum_{i=0..n-j-k} (-1)^(n-i-j-k)*C(2k+i,i)*C(n-i-j-1,n-i-j-k) for n>k with T(n,n)=1 for n>=0. - Paul D . Hanna (pauldhanna(AT)juno.com), Jun 21 2006

PROG

(PARI) {T(n, k)=if(n==k, 1, sum(j=0, k, T(k, j)*sum(i=0, n-j-k, (-1)^(n-i-j-k)*binomial(2*k+i, i)*binomial(n-i-j-1, n-i-j-k))))} - Paul D . Hanna (pauldhanna(AT)juno.com), Jun 21 2006

KEYWORD

nonn,tabl,new

AUTHOR

Paul D . Hanna (pauldhanna(AT)juno.com), Nov 15 2005

#2 by N. J. A. Sloane at Fri Sep 29 03:00:00 EDT 2006
FORMULA

T(n,k) = Sum_{j=0..k} T(k,j)*Sum_{i=0..n-j-k} (-1)^(n-i-j-k)*C(2k+i,i)*C(n-i-j-1,n-i-j-k) for n>k with T(n,n)=1 for n>=0. - Paul D Hanna (pauldhanna(AT)juno.com), Jun 21 2006

EXAMPLE

Where where g.f. for columns is formed from g.f. of rows:

column 2: (1 + 3*x + 1*x^2)/(1-x)^3/(1-x^2)^2 = 1 + 6*x + 18*x^2 + 43*x^3 + 86*x^4 + 156*x^5 +...

= column 3: (1 + 6*x + 166*x^2 + 1*x^3)/(1-x)^4/(1-x^2)^3 = 1 + 10*x + 43*x^2 + 31135*x^3 + 51345*x^4 + 76771*x^5 +...

column 34: (1 + 610*x + 618*x^2 + 110*x^3 + 1*x^4)/(1-x)^5/(1-x^2)^4/( = 1- + 15*x + 87*x^2) + 345*x^3 + 1083*x^4 + 2901*x^5 +...

= 1 + 10*x + 43*x^2 + 135*x^3 + 345*x^4 + 771*x^5 +...

column 4: (1 + 10*x + 18*x^2 + 10*x^3 + 1*x^4)/(1-x)^5/(1-x^2)^4

= 1 + 15*x + 87*x^2 + 345*x^3 + 1083*x^4 + 2901*x^5 +...

PROG

(PARI) {T(n, k)=if(n==k, 1, sum(j=0, k, T(k, j)*sum(i=0, n-j-k, (-1)^(n-i-j-k)*binomial(2*k+i, i)*binomial(n-i-j-1, n-i-j-k))))} - Paul D Hanna (pauldhanna(AT)juno.com), Jun 21 2006

CROSSREFS

Cf. A114173 A114177 (row sums), A114174 (central terms), A114175 (row sums-square).

KEYWORD

nonn,tabl,new

#1 by N. J. A. Sloane at Tue Jan 24 03:00:00 EST 2006
NAME

Triangle, read by rows, where the g.f. of column n, C_n(x), equals the g.f. of row n, R_n(x), divided by (1-x)^(n+1)*(1-x^2)^n, for n>=0; e.g., C_n(x) = R_n(x)/(1-x)^(n+1)/(1-x^2)^n.

DATA

1, 1, 1, 1, 3, 1, 1, 6, 6, 1, 1, 10, 18, 10, 1, 1, 15, 43, 43, 15, 1, 1, 21, 86, 135, 87, 21, 1, 1, 28, 156, 345, 345, 159, 28, 1, 1, 36, 260, 771, 1083, 777, 267, 36, 1, 1, 45, 410, 1557, 2901, 2927, 1577, 423, 45, 1, 1, 55, 615, 2913, 6909, 9219, 7001, 2973, 637, 55, 1

OFFSET

0,5

EXAMPLE

Triangle begins:

1;

1,1;

1,3,1;

1,6,6,1;

1,10,18,10,1;

1,15,43,43,15,1;

1,21,86,135,87,21,1;

1,28,156,345,345,159,28,1;

1,36,260,771,1083,777,267,36,1;

1,45,410,1557,2901,2927,1577,423,45,1;

1,55,615,2913,6909,9219,7001,2973,637,55,1; ...

Where g.f. for columns is formed from g.f. of rows:

column 2: (1 + 3*x + 1*x^2)/(1-x)^3/(1-x^2)^2

= 1 + 6*x + 16*x^2 + 31*x^3 + 51*x^4 + 76*x^5 +...

column 3: (1 + 6*x + 6*x^2 + 1*x^3)/(1-x)^4/(1-x^2)^3

= 1 + 10*x + 43*x^2 + 135*x^3 + 345*x^4 + 771*x^5 +...

column 4: (1 + 10*x + 18*x^2 + 10*x^3 + 1*x^4)/(1-x)^5/(1-x^2)^4

= 1 + 15*x + 87*x^2 + 345*x^3 + 1083*x^4 + 2901*x^5 +...

PROG

(PARI) {T(n, k)=if(n<k|k<0, 0, if(n==k|k==0, 1, polcoeff(sum(j=0, k, T(k, j)*x^j)/(1-x+x*O(x^(n-k)))^(k+1)/(1-x^2)^k, n-k)))}

CROSSREFS

Cf. A114173 (row sums), A114174 (central terms), A114175 (row sums-square).

KEYWORD

nonn,tabl

AUTHOR

Paul D Hanna (pauldhanna(AT)juno.com), Nov 15 2005

STATUS

approved