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.

A372723 Triangle read by rows: Column k has e.g.f. t^k / ((1 - t)^(k + 1) * exp(t)).

Original entry on oeis.org

1, 0, 1, 1, 2, 2, 2, 9, 12, 6, 9, 44, 84, 72, 24, 44, 265, 640, 780, 480, 120, 265, 1854, 5430, 8520, 7560, 3600, 720, 1854, 14833, 50988, 97650, 112560, 78120, 30240, 5040, 14833, 133496, 526568, 1189104, 1681680, 1525440, 866880, 282240, 40320
Offset: 0

Views

Author

Peter Luschny, May 21 2024

Keywords

Examples

			Triangle starts:
[0]     1;
[1]     0,      1;
[2]     1,      2,      2;
[3]     2,      9,     12,       6;
[4]     9,     44,     84,      72,      24;
[5]    44,    265,    640,     780,     480,     120;
[6]   265,   1854,   5430,    8520,    7560,    3600,    720;
[7]  1854,  14833,  50988,   97650,  112560,   78120,  30240,   5040;
[8] 14833, 133496, 526568, 1189104, 1681680, 1525440, 866880, 282240, 40320;
		

Crossrefs

Cf. A000166 (column 0), A000142 (main diagonal), A062119 (subdiagonal), A000354 (row sums), A033999 (alternating row sums), A372716 (central terms).

Programs

  • Maple
    MAX := 14; gf := k -> t^k / ((1 - t)^(k + 1) * exp(t)):
    ser := k -> series(gf(k), t, MAX):
    col := k -> local n; seq(n!*coeff(series(ser(k), t, MAX-1), t, n), n = 0..MAX-2):
    T := (n, k) -> col(k)[n+1]:
    seq(lprint(seq(T(n, k), k = 0..n)), n = 0..8);