75424

Appears in sequences

• Numbers k such that k * (k+5) gives the concatenation of two numbers m and m+5.at n=4A116324
• a(1) = 1. a(n) = sum of the earlier terms of the sequence, a(k), where GCD(n,a(k)) is <= k, for 1 <= k <= n-1.at n=20A119990
• a(n) = n*(7*n^2 - 3*n - 1)/3.at n=32A214659