A226998 The number of descents over all functions f:{1,2,...,n}->{1,2,...,n}.
0, 1, 18, 288, 5000, 97200, 2117682, 51380224, 1377495072, 40500000000, 1296871230050, 44952006426624, 1677462128818632, 67068898339975168, 2860906750488281250, 129703669268270284800, 6228632560085359165568, 315864220382241648869376, 16868630748261621128320242
Offset: 1
Keywords
Crossrefs
Cf. A225753.
Programs
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Mathematica
Table[(n + 1/n -2)*n^n/2,{n,1,20}]
Formula
a(n) = (n + 1/n -2)*n^n/2 = A062023(n) - n^n.
Comments