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.

A140275 Total number of distinct solutions (modulo lcm(1,2,...,n)) of the system of congruences x == i (mod p(i)), i=1,2,...,n, where p is a permutation of order n.

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%I A140275 #9 Dec 07 2019 22:29:39
%S A140275 1,2,5,8,32,20,120,112,172,80,1164,312,5160,1852,812,432,10168
%N A140275 Total number of distinct solutions (modulo lcm(1,2,...,n)) of the system of congruences x == i (mod p(i)), i=1,2,...,n, where p is a permutation of order n.
%C A140275 The system of congruences x == i (mod p(i)) has the same solution as the system of congruences x == n-1-i (mod p'(i)) where p'=(p(n),p(n-1),...,p(1)). Therefore this sequence also gives the number of distinct solutions to the system of congruences x == -i (mod p(i)), i=1,2,...,n.
%C A140275 a(n) <= A140257(n).
%Y A140275 Cf. A003418, A138588, A140257.
%K A140275 nonn,more
%O A140275 1,2
%A A140275 _Max Alekseyev_, May 16 2008