A240473 Distance from prime(n) to the closest smaller squarefree number.

1, 1, 2, 1, 1, 2, 2, 2, 1, 3, 1, 2, 2, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 4, 1, 1, 2, 2, 4, 1, 3, 1, 3, 2, 2, 2, 1, 3, 1, 2, 1, 2, 2, 2, 1, 1, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 3, 3, 1, 2, 2, 1, 2, 3, 1, 2, 1, 2, 4, 1, 1, 2, 2, 1, 3, 2, 2, 2, 1, 2, 1, 2, 1, 1

Offset: 1

Author

Chris Boyd, Apr 06 2014

Keywords

• nonn

Examples

			a(10) = 3 because 3 is the gap between prime(10) = 29 and the closest smaller squarefree number 26.
		

Links

• Chris Boyd, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A112925, A166003, A176141, A240474, A240475, A240476.

Programs

PARI

forprime(p=1,450,forstep(j=p-1,1,-1,if(issquarefree(j),print1(p-j", ");break)))

Formula

a(n) = A000040(n) - A112925(n). - Michel Marcus, Apr 10 2014