A167758 Numbers k such that d(k) = nonisolated nonprime.

1, 24, 30, 36, 40, 42, 48, 54, 56, 66, 70, 78, 80, 88, 100, 102, 104, 105, 110, 112, 114, 120, 128, 130, 135, 136, 138, 144, 152, 154, 162, 165, 168, 170, 174, 176, 182, 184, 186, 189, 190, 192, 195, 196, 208, 210, 216, 222, 225, 230, 231, 232, 238, 240, 246

Offset: 1

Author

Juri-Stepan Gerasimov, Nov 10 2009

Keywords

• nonn

Comments

Where 0, 1, 8, 9, 10, 14, 15, 16, 20,.. are nonisolated nonprimes A164276. Numbers k such that number of divisors of k is nonisolated nonprime. Or, the positions of nonisolated nonprimes in A000005.

Examples

			A000005(1=a(1))=1; A000005(24=a(2))=8; A000005(30=a(3))=8; A000005(36=a(4))=9.
		

Crossrefs

Cf. A000005, A164276.

Formula

A000005(a(n))=nonisolated nonprime.

Extensions

Corrected (152 inserted) by R. J. Mathar, May 30 2010