**a(n) is the smallest number N such that sigma(N) is an n-th power but not a higher power, with a(n) = 0 if no such number exists.**

*1, 2, 3, 7, 510, 21, 17490, 93, 217, 381, 651, 118879530, 2667, 8191, 11811, 24573*

*9 seqfan posts*

*Fri Feb 25 20:25:16 CET 2011* [seqfan] Re: Empirical relation for A180169: Sigma(A180162(n)), where A180162(n) is the smallest N such that sigma(N) is an nth power, or 0 if no such N can be found

*Fri Feb 25 17:25:31 CET 2011* [seqfan] Re: Empirical relation for A180169: Sigma(A180162(n)), where A180162(n) is the smallest N such that sigma(N) is an nth power, or 0 if no such N can be found

*Fri Feb 25 16:59:32 CET 2011* [seqfan] Re: Empirical relation for A180169: Sigma(A180162(n)), where A180162(n) is the smallest N such that sigma(N) is an nth power, or 0 if no such N can be found

*Fri Feb 25 16:45:07 CET 2011* [seqfan] Empirical relation for A180169: Sigma(A180162(n)), where A180162(n) is the smallest N such that sigma(N) is an nth power, or 0 if no such N can be found

*Tue Nov 2 03:17:25 CET 2010* [seqfan] Clarification: Sequence of the Day page is for "transclusion"

*Thu Aug 19 17:02:49 CEST 2010* [seqfan] Re: Definition of sigma(n) which are powers, A180162

*Wed Aug 18 21:26:06 CEST 2010* [seqfan] Re: Definition of sigma(n) which are powers, A180162

*Wed Aug 18 21:34:35 CEST 2010* [seqfan] Re: Definition of sigma(n) which are powers, A180162

*Wed Aug 18 20:41:07 CEST 2010* [seqfan] Definition of sigma(n) which are powers, A180162

Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword

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