A228363 Sorted entries of the multiplication table a*b, with a>1, b>1.

4, 6, 6, 8, 8, 9, 10, 10, 12, 12, 12, 12, 14, 14, 15, 15, 16, 16, 16, 18, 18, 18, 18, 20, 20, 20, 20, 21, 21, 22, 22, 24, 24, 24, 24, 24, 24, 25, 26, 26, 27, 27, 28, 28, 28, 28, 30, 30, 30, 30, 30, 30, 32, 32, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 36, 36, 36, 38, 38, 39, 39, 40, 40, 40, 40

Offset: 1

Author

Ralf Stephan, Aug 21 2013

Keywords

• nonn

Comments

Consists of the composite numbers (A002808), with the composite nonsquares (A089229) occurring more than once, i.e., the n-th composite appears A144925(n) times.

A complement of the primes (A000040).

Crossrefs

Cf. A061017 (sorted entries of standard multiplication table)

Programs

PARI

L=listcreate();for(k=2,250,for(l=2,250,listput(L,k*l)));v=vecsort(Vec(L));for(n=1,100,print1(v[n],","))