A017200 a(n) = (9*n+3)^4.

81, 20736, 194481, 810000, 2313441, 5308416, 10556001, 18974736, 31640625, 49787136, 74805201, 108243216, 151807041, 207360000, 276922881, 362673936, 466948881, 592240896, 741200625, 916636176

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 (5,-10,10,-5,1)

Crossrefs

Cf. A000583 (n^4), A016780 ((3n+1)^4), A017197 (9n+3).

Programs

Magma

[(9*n+3)^4: n in [0..30]]; // Vincenzo Librandi, Jul 23 2011

Mathematica

Table[(9n+3)^4,{n,0,100}] (* Mohammad K. Azarian, Jun 15 2016 *)
LinearRecurrence[{5,-10,10,-5,1},{81,20736,194481,810000,2313441},20] (* Harvey P. Dale, May 26 2023 *)

Formula

a(n) = A000583(A017197(n)). - Michel Marcus, Nov 06 2015

a(n) = 81*A016780(n). - Michel Marcus, Nov 06 2015

From Ilya Gutkovskiy, Jun 16 2016: (Start)

G.f.: 81*(1 + 251*x + 1131*x^2 + 545*x^3 + 16*x^4)/(1 - x)^5.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). (End)