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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.

A206764 a(n) = Sum_{k=1..n} binomial(n,k) * sigma(n,k) * (-1)^(n-k).

Table of values

n a(n)
1 1
2 -1
3 10
4 79
5 1026
6 15686
7 279938
8 5771359
9 134218243
10 3487832974
11 100000000002
12 3138673052878
13 106993205379074
14 3937454749863382
15 155568096631586820
16 6568441588686506943
17 295147905179352825858
18 14063102470280932000757
19 708235345355337676357634

List of values

[1, -1, 10, 79, 1026, 15686, 279938, 5771359, 134218243, 3487832974, 100000000002, 3138673052878, 106993205379074, 3937454749863382, 155568096631586820, 6568441588686506943, 295147905179352825858, 14063102470280932000757, 708235345355337676357634]

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

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