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.

A252866 Number T(n,k) of parts p in all partitions of n with largest integer power k (such that A052409(p)=k); triangle T(n,k), n>=1, 0<=k<=A000523(n), read by rows.

Original entry on oeis.org

1, 2, 1, 4, 2, 7, 4, 1, 12, 7, 1, 19, 14, 2, 30, 21, 3, 45, 34, 6, 1, 67, 51, 9, 1, 97, 79, 14, 2, 139, 113, 20, 3, 195, 168, 31, 5, 272, 234, 43, 7, 373, 334, 62, 11, 508, 460, 85, 15, 684, 635, 120, 23, 1, 915, 857, 161, 31, 1, 1212, 1165, 221, 44, 2, 1597
Offset: 1

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Author

Alois P. Heinz, Dec 23 2014

Keywords

Examples

			Triangle T(n,k) begins:
01:    1;
02:    2,   1;
03:    4,   2;
04:    7,   4,   1;
05:   12,   7,   1;
06:   19,  14,   2;
07:   30,  21,   3;
08:   45,  34,   6,  1;
09:   67,  51,   9,  1;
10:   97,  79,  14,  2;
11:  139, 113,  20,  3;
12:  195, 168,  31,  5;
13:  272, 234,  43,  7;
14:  373, 334,  62, 11;
15:  508, 460,  85, 15;
16:  684, 635, 120, 23,  1;
		

Crossrefs

Column k=0 gives A000070(n-1).
Row sums give: A006128.

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, [1, 0], `if`(i<1, 0,
          add((p-> p+[0, p[1]*j*x^igcd(seq(h[2], h=ifactors(i)[2]))]
          )(b(n-i*j, i-1)), j=0..n/i)))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n$2)[2]):
    seq(T(n), n=1..25);

Formula

T(2^k,k) = 1.