OFFSET
0,3
LINKS
Harry J. Smith, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
a(n) = (n^7 - n)/(6n - 6) = A053700(n)*n/6.
G.f.: x*(1+14*x+56*x^2+42*x^3+7*x^4)/(1-x)^7. [Colin Barker, May 08 2012]
EXAMPLE
a(2) = (2 + 4 + 8 + 16 + 32 + 64)/6 = 126/6 = 21.
MATHEMATICA
Table[Total[n^Range[6]]/6, {n, 0, 30}] (* Harvey P. Dale, Jan 29 2011 *)
PROG
(PARI) { for (n=0, 1000, if (n==1, a=1, a=(n^7 - n)/(6*n - 6)); write("b059721.txt", n, " ", a); ) } \\ Harry J. Smith, Jun 28 2009
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Henry Bottomley, Feb 07 2001
STATUS
approved