A064984 - OEIS

A064984

Triangle of coefficients T[n,m] of polynomials n, n^2, (n+2n^3)/3, n^2(2+n^2)/3, n(3+10n^2+2n^4)/15, etc. after multiplication by the denominators (A049606).

1, 0, 1, 1, 0, 2, 0, 2, 0, 1, 3, 0, 10, 0, 2, 0, 23, 0, 20, 0, 2, 45, 0, 196, 0, 70, 0, 4, 0, 132, 0, 154, 0, 28, 0, 1, 315, 0, 1636, 0, 798, 0, 84, 0, 2, 0, 5067, 0, 7180, 0, 1806, 0, 120, 0, 2, 14175, 0, 83754, 0, 50270, 0, 7392, 0, 330, 0, 4, 0, 146430, 0, 239327, 0, 74800, 0

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OFFSET

1,6

COMMENTS

These polynomials are P(1, n) = 2*Sum[k, {k,1,n-1}] + n, counting up to n and down again; P(2, m) = 2*Sum[P(1,n), {n,1,m-1}] + P(1,m), meaning up and down to n and this for n from 1 up to m and down again; etc.

LINKS

Table of n, a(n) for n=1..73.

EXAMPLE

1+2+3+2+1 = 3^2, (1)+(1+2+1)+(1+2+3+2+1)+(1+2+1)+(1) = (n+2n^3)/3.

MATHEMATICA

CoefficientList[ #, n ]&/@(NestList[ ((2*Sum[ #, {n, k-1} ]+(#/. n->k)//Simplify)/.k->n)&, n, -1+16 ] Denominator[ 2^#/#!&/@Range[ 16 ] ])

CROSSREFS

Row sums give A049606 again, final entry in each row seems to give A048896.

Sequence in context: A265247 A022879 A340524 * A323226 A307197 A328949

Adjacent sequences: A064981 A064982 A064983 * A064985 A064986 A064987

KEYWORD

nonn,tabl

AUTHOR

Wouter Meeussen, Oct 30 2001

STATUS

approved