Sum of the squares of the trinomial coefficients (A027907).
1, 3, 19, 141, 1107, 8953, 73789, 616227, 5196627, 44152809, 377379369
2 seqfan posts
Thu Jul 23 22:03:28 CEST 2009 [seqfan] Re: A071816, A005900
Thu Jul 23 18:37:37 CEST 2009 [seqfan] A071816, A005900
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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