A016987 a(n) = (7*n)^7.

0, 823543, 105413504, 1801088541, 13492928512, 64339296875, 230539333248, 678223072849, 1727094849536, 3938980639167, 8235430000000, 16048523266853, 29509034655744, 51676101935731

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Comments

a(n) = A155955(n,7) for n > 6. - Reinhard Zumkeller, Jan 31 2009

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (8, -28, 56, -70, 56, -28, 8, -1).

Programs

Magma

[(7*n)^7: n in [0..25]]; // Vincenzo Librandi, Jun 18 2011

Mathematica

(7*Range[0,20])^7 (* or *) LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{0,823543,105413504,1801088541,13492928512,64339296875,230539333248,678223072849},20] (* Harvey P. Dale, Apr 01 2013 *)

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)=0, a(1)=823543, a(2)=105413504, a(3)=1801088541, a(4)=13492928512, a(5)=64339296875, a(6)=230539333248, a(7)=678223072849. - Harvey P. Dale, Apr 01 2013