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

Author

M. F. Hasler, Mar 10 2009

Keywords

• nonn

Comments

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

Links

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

Crossrefs

Cf. A157941.

Programs

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 */

Formula

Equals A157936 \ A001248 = A157938 union A006094.