Sophie Germain triangular numbers tr: 2*tr+1 is also a triangular number.
0, 1, 10, 45, 351, 1540, 11935, 52326, 405450, 1777555, 13773376, 60384555
3 seqfan posts
Sat Mar 13 00:55:32 CET 2010 [seqfan] Re: Sophie Germain pentagonal numbers
Sat Mar 13 00:37:31 CET 2010 [seqfan] Re: Sophie Germain pentagonal numbers
Sat Mar 13 00:11:32 CET 2010 [seqfan] Sophie Germain pentagonal numbers
Index of A-numbers in seqfan: by ascending order
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