A017227 a(n) = (9*n + 5)^7.

78125, 105413504, 3404825447, 34359738368, 194754273881, 781250000000, 2488651484819, 6722988818432, 16048523266853, 34792782221696, 69833729609375, 131593177923584, 235260548044817, 402271083010688

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..10000
• Index entries for linear recurrences with constant coefficients, signature (8, -28, 56, -70, 56, -28, 8, -1).

Programs

Magma

[(9*n+5)^7: n in [0..20]]; // Vincenzo Librandi, Jul 24 2011

Mathematica

(9*Range[0,20]+5)^7 (* or *) LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{78125,105413504,3404825447,34359738368,194754273881,781250000000,2488651484819,6722988818432},20] (* Harvey P. Dale, Apr 13 2014 *)

Formula

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8); a(0)=78125, a(1)=105413504, a(2)=3404825447, a(3)=34359738368, a(4)=194754273881, a(5)=781250000000, a(6)=2488651484819, a(7)=6722988818432. - Harvey P. Dale, Apr 13 2014