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.

A225860 Number of partitions of 2^n into binomial coefficients C(n,k).

Original entry on oeis.org

1, 1, 3, 3, 10, 16, 55, 133, 599, 1956, 11982, 57872, 477289, 3290993, 37671322, 373566217, 5986589127, 85738839408, 1931359427404, 40003346563574, 1274368885871702, 38222180804346119, 1729302096638372691, 75195441157176495562, 4848355840082055530710
Offset: 0

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Author

Reinhard Zumkeller, May 26 2013

Keywords

Examples

			n=3: C(3,0)=C(3,3) = 1, C(3,1)=C(3,2) = 3, 2^3 = 8:
a(3) = #{3+3+1+1, 3+1+1+1+1+1, 8x1} = 3;
n=4: C(4,0)=C(4,4) = 1, C(4,1)=C(4,3) = 4, C(4,2) = 6, 2^4 = 16:
a(4) = #{6+6+4, 6+6+1+1+1+1, 6+4+4+1+1, 6+4+6x1, 6+10x1, 4+4+4+4, 4+4+4+1+1+1+1, 4+4+8x1, 4+12x1, 16x1} = 10
n=5: C(5,0)=C(5,5) = 1, C(5,1)=C(5,4) = 5, C(5,2)=C(5,3) = 10, 2^5 = 32:
a(5) = #{10+10+10+1+1, 10+10+5+5+1+1, 10+10+5+7x1, 10+10+12x1, 10+5+5+5+5+1+1, 10+5+5+5+7x1, 10+5+5+12x1, 10+5+17x1, 10+22x1, 6x5, 5x5+7x1, 5+5+5+5+12x1, 5+5+5+17x1, 5+5+22x1, 5+27x1, 32x1} = 16.
		

Crossrefs

Programs

  • Haskell
    a225860 n = p (a034868_row n) (2 ^ n) where
       p _          0 = 1
       p []         _ = 0
       p bs'@(b:bs) m = if m < b then 0 else p bs' (m - b) + p bs m
  • Maple
    a:= proc(n) option remember; local g, i, j, l, m, t;
          m:= 1+iquo(n, 2);
          l:= array(1..m, [seq(binomial(n,k), k=0..m-1)]);
          g:= array(1..m, [seq(array(0..l[i]-1, [0$(l[i])]), i=1..m)]);
          g[1][0]:= 1;
          for j from 0 to 2^n do for i from 2 to m do
            g[i][irem(j, l[i])]:= g[i][irem(j, l[i])]
                                 +g[i-1][irem(j, l[i-1])]
          od od; g[m][irem(2^n, l[m])]
        end:
    seq(a(n), n=0..14);  # Alois P. Heinz, May 30 2013

Extensions

a(13)-a(23) from Alois P. Heinz, May 30 2013
a(24) from Alois P. Heinz, Oct 06 2014