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.

A064349 Generating function: 1/((1-x)*(1-x^2)^2*(1-x^3)^3*(1-x^4)^4).

Original entry on oeis.org

1, 1, 3, 6, 13, 19, 37, 58, 97, 143, 227, 328, 492, 688, 992, 1364, 1903, 2551, 3473, 4586, 6097, 7911, 10333, 13226, 16988, 21454, 27172, 33938, 42437, 52423, 64833, 79354, 97130, 117824, 142930, 172018, 206925, 247179, 295105, 350154, 415124
Offset: 0

Views

Author

Henry Bottomley, Sep 17 2001

Keywords

Comments

Number of partitions of n into parts 1 (of one kind), 2 (of two kinds), 3 (of three kinds), and 4 (of 4 kinds). [Joerg Arndt, Jul 11 2013]

Crossrefs

The sequence of sequences A000007, A000012, A008805, A002597, A064349, etc. approaches A000219.
Essentially the same as A002598.
Cf. A002598.

Programs

  • PARI
    a(n) = floor( ([13, 28, -44][n%3+1]+(9/2)*(n\3+2)*((n+1)%3-1)) * (n\3+1)/729 - (n\2+1)*(-1)^(n\2) * (3*[-8, 11]+(n\2+2)*(2*[-1, 3]+(n\2+3)*(1/3)*[0, 1]))[n%2+1]/512 + (2*n^9 +270*n^8 +15600*n^7 +504000*n^6 +9977730*n^5 +124629750*n^4 +973069200*n^3 +4521339000*n^2 +11137512613*n +16461579435 +5103*(n+15)*(2*n^4 +120*n^3 +2440*n^2 +19200*n +48213)*(-1)^n) / 20065812480 ) \\ Tani Akinari, Jul 12 2013
    
  • PARI
    Vec(1/((1-x)*(1-x^2)^2*(1-x^3)^3*(1-x^4)^4)+O(x^66)) \\ Joerg Arndt, Jul 11 2013