A157937 Numbers n divisible by the least prime >= sqrt(n) which are not in A001248 (primes squared).

6, 10, 15, 20, 28, 35, 42, 55, 66, 77, 88, 99, 110, 130, 143, 156, 170, 187, 204, 221, 238, 255, 272, 304, 323, 342, 368, 391, 414, 437, 460, 483, 506, 551, 580, 609, 638, 667, 696, 725, 754, 783, 812, 868, 899, 930, 962, 999, 1036, 1073, 1110, 1147, 1184, 1221

Offset

1,1

Comments

A subsequence of A157936, contains A157938 as subsequence: cf. formulas.

Links

Hugo Pfoertner, Table of n, a(n) for n = 1..10000

Formula

Equals A157936 \ A001248 = A157938 union A006094.

Prog

(PARI) for( n=5, 1999, n % nextprime(sqrtint(n-1)+1) & next; omega(n)>1 & print1(n", ")) /* sqrtint(n-1)+1 avoids rounding errors but could be replaced by sqrt(n) for small n */

Crossrefs

Cf. A157941.

Sequence in context: A315265 A315266 A315267 * A080255 A337185 A324972

Adjacent sequences: A157934 A157935 A157936 * A157938 A157939 A157940

Keyword

nonn

Author

M. F. Hasler, Mar 10 2009

Status

approved