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.

A265018 Total sum T(n,k) of number of lambda-parking functions of partitions lambda of n into distinct parts with largest part k; triangle T(n,k), n>=0, floor(sqrt(2n)+1/2)<=k<=n, read by rows.

Original entry on oeis.org

1, 1, 2, 3, 3, 5, 4, 8, 7, 5, 16, 12, 9, 6, 40, 16, 11, 7, 34, 55, 20, 13, 8, 50, 73, 70, 24, 15, 9, 125, 132, 96, 85, 28, 17, 10, 281, 212, 119, 100, 32, 19, 11, 351, 469, 267, 142, 115, 36, 21, 12, 307, 642, 644, 322, 165, 130, 40, 23, 13
Offset: 0

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Author

Alois P. Heinz, Nov 30 2015

Keywords

Examples

			Triangle T(n,k) begins:
00 :  1;
01 :     1;
02 :        2;
03 :        3,  3;
04 :            5,   4;
05 :            8,   7,   5;
06 :           16,  12,   9,   6;
07 :                40,  16,  11,   7;
08 :                34,  55,  20,  13,   8;
09 :                50,  73,  70,  24,  15,   9;
10 :               125, 132,  96,  85,  28,  17, 10;
11 :                    281, 212, 119, 100,  32, 19, 11;
12 :                    351, 469, 267, 142, 115, 36, 21, 12;
		

Crossrefs

Row sums give A265016.
Column sums give A265130.
Cf. A000217, A000272, A002024, A265019 (the same read by columns).

Programs

  • Maple
    p:= l-> (n-> n!*LinearAlgebra[Determinant](Matrix(n, (i, j)
             -> (t->`if`(t<0, 0, l[i]^t/t!))(j-i+1))))(nops(l)):
    g:= (n, i, l)-> `if`(i*(i+1)/2n, 0, g(n-i, i-1, [i, l[]])))):
    T:= n->(f->seq(coeff(f, x, i), i=ldegree(f)..degree(f)))(g(n$2, [])):
    seq(T(n), n=0..20);

Formula

T(A000217(n),n) = A000272(n+1).