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A277455
Arithmetic derivatives of the Motzkin numbers.
0
0, 0, 1, 4, 6, 10, 20, 1, 36, 172, 2192, 3371, 1, 22327, 135561, 517656, 284492, 933118, 5446991, 24265724, 18238138, 93800069, 334654476, 1368408363, 2584589232, 1823879615, 25669818480, 41583822879, 1967330543, 29409700520, 1265785403, 3239855363874
OFFSET
0,4
FORMULA
a(n) = A003415(A001006(n)).
a(n) = 1 for n in A092831.
MATHEMATICA
Table[If[Abs@ # < 2, 0, # Total[#2/#1 & @@@ FactorInteger[Abs@ #]]] &@ Hypergeometric2F1[(1 - n)/2, -n/2, 2, 4], {n, 0, 31}] (* Michael De Vlieger, Oct 17 2016, after Michael Somos at A003415 and Peter Luschny at A001006 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul Bedard, Oct 16 2016
EXTENSIONS
More terms from Alois P. Heinz, Oct 16 2016
STATUS
approved