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

1,1

Comments

No two consecutive positive integers m and m+1 are both non-coprime to any particular power of a prime.

Links

Table of n, a(n) for n=1..83.

Example

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.

Sequence in context: A340148 A049200 A347100 * A325965 A198540 A216369

Adjacent sequences: A164698 A164699 A164700 * A164702 A164703 A164704

Keyword

nonn

Author

Leroy Quet, Aug 22 2009

Extensions

Extended by Ray Chandler, Mar 15 2010

Status

approved