A016951 a(n) = (6*n + 3)^7.

2187, 4782969, 170859375, 1801088541, 10460353203, 42618442977, 137231006679, 373669453125, 897410677851, 1954897493193, 3938980639167, 7446353252589, 13348388671875, 22876792454961, 37725479487783, 60170087060757, 93206534790699, 140710042265625, 207616015289871

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..2000
• Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1).

Crossrefs

Cf. A016759, A016945, A016946, A016947, A016948, A016949, A016950.

Subsequence of A001015.

Programs

Magma

[(6*n+3)^7: n in [0..40]]; // Vincenzo Librandi, May 05 2011

Mathematica

a[n_] := (6*n + 3)^7; Array[a, 50, 0] (* Amiram Eldar, Mar 30 2022 *)

Formula

From Amiram Eldar, Mar 30 2022: (Start)

a(n) = A016945(n)^7.

a(n) = 3^7*A016759(n).

Sum_{n>=0} 1/a(n) = 127*zeta(7)/279936.

Sum_{n>=0} (-1)^n/a(n) = 61*Pi^7/403107840. (End)