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.

A331709 Number of nonnegative integer matrices with n columns and any number of distinct nonzero rows with column sums 2 and columns in nonincreasing lexicographic order.

Table of values

n a(n)
0 1
1 1
2 7
3 59
4 701
5 10460
6 190816
7 4098997
8 101523139
9 2847014941
10 89188733362
11 3086888531896
12 116982554539226
13 4817701229837597
14 214245144969388823
15 10231975601963484807
16 522307300100522413863
17 28379690860876378241538
18 1635356759307997113784404

List of values

[1, 1, 7, 59, 701, 10460, 190816, 4098997, 101523139, 2847014941, 89188733362, 3086888531896, 116982554539226, 4817701229837597, 214245144969388823, 10231975601963484807, 522307300100522413863, 28379690860876378241538, 1635356759307997113784404]

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

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