A016972 a(n) = (6*n + 5)^4.

625, 14641, 83521, 279841, 707281, 1500625, 2825761, 4879681, 7890481, 12117361, 17850625, 25411681, 35153041, 47458321, 62742241, 81450625, 104060401, 131079601, 163047361, 200533921, 244140625, 294499921, 352275361, 418161601, 492884401, 577200625, 671898241

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Crossrefs

Cf. A016969, A016970, A016971.

Subsequence of A000583.

Programs

Magma

[(6*n+5)^4: n in [0..40]]; // Vincenzo Librandi, May 07 2011

Mathematica

Table[(6 n + 5)^4, {n, 0, 20}] (* Michael De Vlieger, Mar 20 2017 *)

Formula

From Chai Wah Wu, Mar 20 2017: (Start)

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

G.f.: (-x^4 - 2396*x^3 - 16566*x^2 - 11516*x - 625)/(x - 1)^5. (End)

From Amiram Eldar, Apr 01 2022: (Start)

a(n) = A016969(n)^4 = A016970(n)^2.

Sum_{n>=0} 1/a(n) = PolyGamma(3, 5/6)/7776. (End)