A167758 Numbers n such that d(n)=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

1,2

Comments

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

Links

Table of n, a(n) for n=1..55.

Formula

A000005(a(n))=nonisolated nonprime.

Example

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

Crossrefs

Cf. A000005, A164276.

Sequence in context: A114635 A077969 A122181 * A248693 A075422 A230195

Adjacent sequences: A167755 A167756 A167757 * A167759 A167760 A167761

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 10 2009

Extensions

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

Status

approved