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Numbers n such that d(n)=nonisolated nonprime.
0

%I #4 Mar 30 2012 18:52:35

%S 1,24,30,36,40,42,48,54,56,66,70,78,80,88,100,102,104,105,110,112,114,

%T 120,128,130,135,136,138,144,152,154,162,165,168,170,174,176,182,184,

%U 186,189,190,192,195,196,208,210,216,222,225,230,231,232,238,240,246

%N Numbers n such that d(n)=nonisolated nonprime.

%C 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.

%F A000005(a(n))=nonisolated nonprime.

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

%Y Cf. A000005, A164276.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Nov 10 2009

%E Corrected (152 inserted) by _R. J. Mathar_, May 30 2010