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.

A075436 Right- or upward-moving paths connecting opposite corners of an n X n chessboard, visiting the diagonal in 0 up to (n-2) intermediate points between start and finish. Equivalently, subdivide the chessboard into 1 up to (n-1) blocks along the diagonal in all possible ways and sum the path-count over all sub-blocks.

Table of values

n a(n)
2 2
3 10
4 52
5 274
6 1452
7 7716
8 41064
9 218722
10 1165564
11 6213100
12 33125336
13 176629268
14 941884088
15 5022886536
16 26786945232
17 142857244674
18 761881733148
19 4063282813596
20 21670523246712
21 115574945807004
22 616395334890408
23 3287425475237496
24 17532874879557552

List of values

[2, 10, 52, 274, 1452, 7716, 41064, 218722, 1165564, 6213100, 33125336, 176629268, 941884088, 5022886536, 26786945232, 142857244674, 761881733148, 4063282813596, 21670523246712, 115574945807004, 616395334890408, 3287425475237496, 17532874879557552]

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

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