A164276 -id:A164276 - cp's OEIS frontend

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

Juri-Stepan Gerasimov, Nov 10 2009

nonn

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.

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

Cf. A000005, A164276.

A000005(a(n))=nonisolated nonprime.

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

A174219 Integers equal to sqrt of A147846(n) + A147846(n+1).

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 11, 12, 13, 17, 18, 19, 23, 29, 30, 31, 37, 41, 42, 43, 47, 53, 59, 60, 61, 67, 71, 72, 73, 79, 83, 89, 97, 101, 102, 103, 107, 108, 109, 113, 127, 131, 137, 138, 139, 149, 150, 151, 157, 163, 167, 173, 179, 180, 181, 191, 192, 193, 197, 198, 199, 211

Offset: 1

Giovanni Teofilatto, Mar 12 2010

nonn

Complement to A164276.

Cf. A000040, A014574, A147846, A164276.

A000040 U A014574.

cp's OEIS Frontend

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

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