Numbers of the form (2^EulerPhi[3^n]-1)/3^n.
1, 1, 7, 9709, 222399981598543
2 seqfan posts
Wed Nov 19 22:41:51 CET 2008 [seqfan] Re: Help needed!
Wed Nov 19 17:44:55 CET 2008 [seqfan] Help needed!
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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