A016926 a(n) = (6*n + 1)^6.

1, 117649, 4826809, 47045881, 244140625, 887503681, 2565726409, 6321363049, 13841287201, 27680640625, 51520374361, 90458382169, 151334226289, 243087455521, 377149515625, 567869252041, 832972004929, 1194052296529, 1677100110841, 2313060765625, 3138428376721

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).

Formula

From Amiram Eldar, Mar 28 2022: (Start)

a(n) = A016921(n)^6 = A016922(n)^3 = A016923(n)^2.

Sum_{n>=0} 1/a(n) = PolyGamma(5, 1/6)/5598720. (End)

Mathematica

(6*Range[0, 20]+1)^6 (* or *) LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {1, 117649, 4826809, 47045881, 244140625, 887503681, 2565726409}, 20] (* Harvey P. Dale, Aug 19 2019 *)

Prog

(Magma) [(6*n+1)^6: n in [0..40]]; // Vincenzo Librandi, May 04 2011

Crossrefs

Cf. A016921, A016922, A016923, A016924, A016925.

Sequence in context: A204075 A235068 A288985 * A016986 A017154 A017250

Adjacent sequences: A016923 A016924 A016925 * A016927 A016928 A016929

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved