A134155 a(n) = 1 + 21 n + 168 n^2 + 588 n^3 + 1029 n^4.

1, 1807, 21883, 100801, 303829, 720931, 1466767, 2680693, 4526761, 7193719, 10895011, 15868777, 22377853, 30709771, 41176759, 54115741, 69888337, 88880863, 111504331, 138194449, 169411621, 205640947, 247392223, 295199941

Offset: 0

Author

Artur Jasinski, Oct 10 2007

Keywords

• nonn
• easy

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).

Crossrefs

Cf. A119617, A134153, A134154, A134158.

Programs

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 *)

PARI

a(n)=1+21*n+168*n^2+588*n^3+1029*n^4 \\ Charles R Greathouse IV, Oct 21 2022

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