73713

Appears in sequences

• Number of permutations of [n] having exactly 8 strong fixed blocks.at n=4A225969
• Consider a number of k digits n = d_(k)*10^(k-1) + d_(k-1)*10^(k-2) + … + d_(2)*10 + d_(1). Sequence lists the numbers n such that Sum_{i=1..k-1}{phi(Sum_{j=1..i}{d_(j)*10^(j-1)})} = Sum_{i=1..k-1}{sigma(Sum_{j=1..i}{d_(k-j+1)*10^(i-j)})} (see example below).at n=24A244069
• Number of points that are the intersections of exactly two semicircles in the configuration A290447(n).at n=40A292103
• a(n) is the number of subsets of the divisors of k which sum to k+1 where k is a number all of whose prime divisors are consecutive primes starting at 2.at n=53A359753