A164701 a(n) = the smallest positive integer such that neither a(n) nor a(n)+1 are coprime to A024619(n), where A024619 is the sequence of positive integers that are not powers of primes.
2, 4, 2, 6, 5, 2, 4, 6, 10, 2, 12, 6, 2, 11, 16, 14, 2, 18, 12, 4, 2, 10, 5, 22, 2, 4, 17, 12, 2, 10, 6, 18, 28, 2, 30, 6, 25, 2, 16, 23, 4, 2, 36, 5, 18, 21, 2, 4, 40, 2, 34, 42, 29, 10, 2, 13, 22, 30, 46, 19, 2, 6, 11, 4, 2, 12, 5, 52, 2, 4, 36, 6, 2, 45, 28, 12, 58, 34, 2, 60, 41, 30, 2
Offset: 1
Keywords
Examples
22 is the 9th positive integer that is not a power of a prime. a(9) = 10 because neither 10 nor 10+1=11 is coprime to 22, and 10 and 11 are the smallest pair of consecutive positive integers where this is the case.
Crossrefs
Cf. A024619.
Extensions
Extended by Ray Chandler, Mar 15 2010
Comments