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.

Showing 1-2 of 2 results.

A262017 The first of five consecutive positive integers the sum of the squares of which is equal to the sum of the squares of six consecutive positive integers.

Original entry on oeis.org

61, 1381, 30361, 666601, 14634901, 321301261, 7053992881, 154866542161, 3400009934701, 74645352021301, 1638797734533961, 35978904807725881, 789897108035435461, 17341757471971854301, 380728767275345359201, 8358691122585626048161, 183510475929608427700381
Offset: 1

Views

Author

Colin Barker, Sep 08 2015

Keywords

Comments

For the first of the corresponding six consecutive positive integers, see A157096.

Examples

			61 is in the sequence because 61^2 + ... + 65^2 = 19855 = 55^2 + ... + 60^2.
		

Crossrefs

Programs

  • PARI
    Vec(-x*(x^2-22*x+61)/((x-1)*(x^2-22*x+1)) + O(x^40))

Formula

a(n) = 23*a(n-1)-23*a(n-2)+a(n-3) for n>3.
G.f.: -x*(x^2-22*x+61) / ((x-1)*(x^2-22*x+1)).

A262018 The first of five consecutive positive integers the sum of the squares of which is equal to the sum of the squares of eleven consecutive positive integers.

Original entry on oeis.org

28, 5308, 945148, 168231388, 29944242268, 5329906892668, 948693482652988, 168862110005339548, 30056506887467786908, 5349889363859260730428, 952250250260060942229628, 169495194656926988456143708, 30169192398682743884251350748, 5369946751770871484408284289788
Offset: 1

Views

Author

Colin Barker, Sep 08 2015

Keywords

Comments

For the first of the corresponding eleven consecutive positive integers, see A262019.

Examples

			28 is in the sequence because 28^2 + ... + 32^2 = 4510 = 15^2 + ... + 25^2.
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{179,-179,1},{28,5308,945148},30] (* Harvey P. Dale, May 16 2019 *)
  • PARI
    Vec(-4*x*(7*x^2+74*x+7)/((x-1)*(x^2-178*x+1)) + O(x^20))

Formula

a(n) = 179*a(n-1)-179*a(n-2)+a(n-3) for n>3.
G.f.: -4*x*(7*x^2+74*x+7) / ((x-1)*(x^2-178*x+1)).
Showing 1-2 of 2 results.