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A127074
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Numbers n such that n^2 divides 3^n - 2^n - 1.
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8
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OFFSET
| 1,2
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COMMENTS
| Prime p divides 3^p - 2^p - 1. Quotients (3^p - 2^p - 1)/p are listed in A127071.
Numbers n such that n divides 3^n - 2^n - 1 are listed in A127072.
The pseudoprimes in A127072 include all powers of primes and some composite numbers that are listed in A127073.
Numbers n such that n^3 divides 3^n - 2^n - 1 are {1,4,7,...}.
Primes in a(n) are {2,3,7,179,619,...}.
No other terms below 10^9.
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MATHEMATICA
| Do[f=(3^n-2^n-1); If[IntegerQ[f/n^2], Print[n]], {n, 1, 1000}]
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CROSSREFS
| Cf. A127071, A127072, A127073.
Sequence in context: A094313 A070527 A158652 * A109617 A181881 A071373
Adjacent sequences: A127071 A127072 A127073 * A127075 A127076 A127077
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KEYWORD
| hard,more,nonn
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AUTHOR
| Alexander Adamchuk (alex(AT)kolmogorov.com), Jan 04 2007
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EXTENSIONS
| 6 incorrect terms deleted by D. S. McNeil (d.mcneil(AT)qmul.ac.uk), Mar 16 2009 (the old version was 1,2,3,4,7,49,179,619,17807,95041,135433,393217,589825,1376257,1545601)
Edited by Max Alekseyev (maxale(AT)gmail.com), Oct 21 2011
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