cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A053699 a(n) = n^4 + n^3 + n^2 + n + 1.

Original entry on oeis.org

1, 5, 31, 121, 341, 781, 1555, 2801, 4681, 7381, 11111, 16105, 22621, 30941, 41371, 54241, 69905, 88741, 111151, 137561, 168421, 204205, 245411, 292561, 346201, 406901, 475255, 551881, 637421, 732541, 837931, 954305, 1082401, 1222981, 1376831, 1544761, 1727605
Offset: 0

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Author

Henry Bottomley, Mar 23 2000

Keywords

Comments

a(n) = 11111 in base n.
a(n) = Phi_5(n), where Phi_k is the k-th cyclotomic polynomial.

Crossrefs

5th row of the array A055129.
Cf. A104878.

Programs

Formula

a(n) = n^4 + n^3 + n^2 + n + 1 = (n^5-1)/(n-1).
G.f.: (1 + 16*x^2 + 6*x^3 + x^4)/(1-x)^5. - Colin Barker, Jan 10 2012
E.g.f.: exp(x)*(1 + 4*x + 11*x^2 + 7*x^3 + x^4). - Stefano Spezia, Oct 03 2024
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). - Wesley Ivan Hurt, Aug 05 2025