A017332 a(n) = (10*n + 5)^4.

625, 50625, 390625, 1500625, 4100625, 9150625, 17850625, 31640625, 52200625, 81450625, 121550625, 174900625, 244140625, 332150625, 442050625, 577200625, 741200625, 937890625, 1171350625, 1445900625, 1766100625, 2136750625, 2562890625, 3049800625, 3603000625

Offset

0,1

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).

Formula

G.f.: -625*(x^4 + 76*x^3 + 230*x^2 + 76*x+1)/(x-1)^5. - Colin Barker, Nov 14 2012

From Amiram Eldar, Apr 18 2023: (Start)

a(n) = A017329(n)^4.

a(n) = 5^4 * A016756(n).

Sum_{n>=0} 1/a(n) = Pi^4/60000. (End)

Mathematica

Table[(10*n + 5)^4, {n, 0, 30}] (* Amiram Eldar, Apr 18 2023 *)
LinearRecurrence[{5, -10, 10, -5, 1}, {625, 50625, 390625, 1500625, 4100625}, 30] (* Harvey P. Dale, Aug 20 2024 *)

Prog

(Magma) [(10*n+5)^4: n in [0..35]]; // Vincenzo Librandi, Aug 02 2011

Crossrefs

Cf. A016756, A017329.

Sequence in context: A180259 A017224 A106321 * A167039 A265932 A017452

Adjacent sequences: A017329 A017330 A017331 * A017333 A017334 A017335

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved