OFFSET
0,2
COMMENTS
All terms == 1 (mod 21). - Robert Israel, Aug 11 2017
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
a(n) = (3*(7*n + 1)^4 + 6*(7*n + 1)^2 - 3*(7*n + 1) + 1)/7.
G.f.: -(1+1802*x+12858*x^2+9446*x^3+589*x^4)/(-1+x)^5. - R. J. Mathar, Nov 14 2007
MAPLE
seq( 1 + 21*n + 168*n^2 + 588*n^3 + 1029*n^4, n=0..30); # Robert Israel, Aug 11 2017
MATHEMATICA
Table[1 + 21 n + 168 n^2 + 588 n^3 + 1029 n^4, {n, 0, 50}]
LinearRecurrence[{5, -10, 10, -5, 1}, {1, 1807, 21883, 100801, 303829}, 30] (* Harvey P. Dale, Aug 29 2021 *)
PROG
(PARI) a(n)=1+21*n+168*n^2+588*n^3+1029*n^4 \\ Charles R Greathouse IV, Oct 21 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Artur Jasinski, Oct 10 2007
STATUS
approved