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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.

A246840 Expansion of Sum_{n>=0} x^n * Sum_{k=0..n} C(n,k)^2 * x^(2*k).

Table of values

n a(n)
0 1
1 1
2 1
3 2
4 5
5 10
6 18
7 35
8 73
9 151
10 306
11 623
12 1286
13 2668
14 5531
15 11477
16 23889
17 49852
18 104175
19 217936
20 456534
21 957609
22 2010839
23 4226417
24 8891022
25 18719637
26 39443860
27 83170162
28 175484915
29 370491775
30 782648333
31 1654197568
32 3498049053
33 7400639286
34 15664103420
35 33168342557
36 70260909811

List of values

[1, 1, 1, 2, 5, 10, 18, 35, 73, 151, 306, 623, 1286, 2668, 5531, 11477, 23889, 49852, 104175, 217936, 456534, 957609, 2010839, 4226417, 8891022, 18719637, 39443860, 83170162, 175484915, 370491775, 782648333, 1654197568, 3498049053, 7400639286, 15664103420, 33168342557, 70260909811]

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

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