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.

A383913 Expansion of (1+x) * (1+2*x) * (1+3*x)/((1-x) * (1-2*x) * (1-3*x) * (1-4*x)).

Original entry on oeis.org

1, 16, 136, 856, 4576, 22216, 101536, 446056, 1907776, 8009416, 33187936, 136233256, 555438976, 2253396616, 9108754336, 36721012456, 147743018176, 593550943816, 2381944320736, 9551006783656, 38273731365376, 153304069611016, 613843773807136, 2457257707146856
Offset: 0

Views

Author

Seiichi Manyama, May 15 2025

Keywords

Crossrefs

Column k=4 of A383818.
Cf. A383911.

Programs

  • PARI
    a(n) = 35*4^n-20*3^(n+1)+15*2^(n+1)-4;

Formula

a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4).
a(n) = Sum_{k=0..4} |Stirling1(4,k)| * Stirling2(k+n,4).
a(n) = 35*4^n - 20*3^(n+1) + 15*2^(n+1) - 4.