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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.

A208977 Self-convolution square-root of A005810, where A005810(n) = binomial(4*n,n).

Table of values

n a(n)
0 1
1 2
2 12
3 86
4 666
5 5388
6 44832
7 380424
8 3275172
9 28512248
10 250413856
11 2215112886
12 19711078686
13 176276723508
14 1583186541144
15 14271487891512
16 129063176166570
17 1170480053359908
18 10641805703955624
19 96970507481607972
20 885397365149468076
21 8098908925136867112

List of values

[1, 2, 12, 86, 666, 5388, 44832, 380424, 3275172, 28512248, 250413856, 2215112886, 19711078686, 176276723508, 1583186541144, 14271487891512, 129063176166570, 1170480053359908, 10641805703955624, 96970507481607972, 885397365149468076, 8098908925136867112]

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

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