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.

A357140 Number of n X n triangular (0,1)-matrices with exactly 2n entries equal to 1 and no zero rows or columns.

Table of values

n a(n)
0 1
1 0
2 0
3 1
4 26
5 865
6 39268
7 2375965
8 185974145
9 18337523130
10 2227232055239
11 327003956573263
12 57121908284696448
13 11712143532463633752
14 2786114854266411595229
15 761208643373263480081077
16 236761580851204534640426709
17 83183218467008383189955036015

List of values

[1, 0, 0, 1, 26, 865, 39268, 2375965, 185974145, 18337523130, 2227232055239, 327003956573263, 57121908284696448, 11712143532463633752, 2786114854266411595229, 761208643373263480081077, 236761580851204534640426709, 83183218467008383189955036015]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.