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A372903
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Numbers k that divide the k-th little Schroeder number.
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1
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1, 33, 2295, 5439, 6699, 7095, 7497, 7595, 10241, 11475, 15345, 19845, 24651, 25245, 35845, 37725, 37791, 49203, 50463, 51183, 51471, 60291, 62073, 64337, 65569, 66495, 68313, 78793, 80223, 81809, 86031, 98167, 100659, 103293, 109395, 115245, 119067, 119919, 142137
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OFFSET
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1,2
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COMMENTS
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Numbers k such that k | A001003(k).
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LINKS
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EXAMPLE
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1 is a term since A001003(1) = 2 is divisible by 1.
33 is a term since A001003(33) = 37836272668898230450209 = 33 * 1146553717239340316673 is divisible by 33.
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MATHEMATICA
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seq[kmax_] := Module[{sc0 = 1, sc1 = 1, sc2, s = {1}}, Do[sc2 = ((6*k-3)*sc1 - (k-2)*sc0)/(k+1); If[Divisible[sc2, k], AppendTo[s, k]]; sc0 = sc1; sc1 = sc2, {k, 2, kmax}]; s]; seq[10^5]
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PROG
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(PARI) lista(kmax) = {my(sc0 = 1, sc1 = 1, sc2); print1(1, ", "); for(k = 2, kmax, sc2 = ((6*k-3)*sc1 - (k-2)*sc0)/(k+1); if(!(sc2 % k), print1(k, ", ")); sc0 = sc1; sc1 = sc2); }
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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