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.

A231304 Recurrence a(n) = a(n-2) + n^M for M=5, starting with a(0)=0, a(1)=1.

Original entry on oeis.org

0, 1, 32, 244, 1056, 3369, 8832, 20176, 41600, 79225, 141600, 240276, 390432, 611569, 928256, 1370944, 1976832, 2790801, 3866400, 5266900, 7066400, 9351001, 12220032, 15787344, 20182656, 25552969, 32064032, 39901876, 49274400, 60413025, 73574400, 89042176
Offset: 0

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Author

Stanislav Sykora, Nov 07 2013

Keywords

Comments

See A231303.

Examples

			a(4) = 4^5 + 2^5 = 1056; a(5) = 5^5 + 3^5 + 1^5 = 3369.
		

Crossrefs

Cf. A001477 (M=1), A000292 (M=2), A105636 (M=3), A231303 (M=4), A231305 (M=6), A231306 (M=7), A231307 (M=8), A231308 (M=9), A231309 (M=10).

Programs

  • Mathematica
    RecurrenceTable[{a[0]==0,a[1]==1,a[n]==a[n-2]+n^5},a,{n,30}] (* or *) LinearRecurrence[{6,-14,14,0,-14,14,-6,1},{0,1,32,244,1056,3369,8832,20176},40] (* Harvey P. Dale, Jul 22 2014 *)
  • PARI
    nmax=100; a = vector(nmax); a[2]=1; for(i=3, #a, a[i]=a[i-2]+(i-1)^5); print(a);
    
  • PARI
    concat(0, Vec(x*(1+26*x+66*x^2+26*x^3+x^4)/((1-x)^7*(1+x)) + O(x^50))) \\ Colin Barker, Dec 22 2015

Formula

a(n) = Sum_{k=0..floor(n/2)} (n-2k)^5.
a(0)=0, a(1)=1, a(2)=32, a(3)=244, a(4)=1056, a(5)=3369, a(6)=8832, a(7)=20176, a(n) = 6*a(n-1) - 14*a(n-2) + 14*a(n-3) - 14*a(n-5) + 14*a(n-6) - 6*a(n-7) + a(n-8). - Harvey P. Dale, Jul 22 2014
From Colin Barker, Dec 22 2015: (Start)
a(n) = (1/24)*(2*n^6 + 12*n^5 + 20*n^4 - 16*n^2 - 3*(-1)^n + 3).
G.f.: x*(1 + 26*x + 66*x^2 + 26*x^3 + x^4) / ((1-x)^7*(1+x)).
(End)