a(n) = C(3*n+1,n)/(n+1).
1, 2, 7, 30, 143, 728, 3876, 21318, 120175, 690690, 4032015, 23841480, 142498692
2 seqfan posts
Sat Dec 4 13:07:56 CET 2010 [seqfan] Re: useless references?
Sat Dec 4 11:56:09 CET 2010 [seqfan] useless references?
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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