**a(1)=a(2)=a(3)=a(4)=1; for n > 4: a(n) = A000720(a(n-1)+a(n-2)+a(n-3)+a(n-4)).**

*1, 1, 1, 1, 2, 3, 4, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 16, 18, 18, 19, 20, 21, 21, 22*

*1 seqfan posts*

Index of A-numbers in seqfan: by ascending order by month by frequency by keyword

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