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A233933
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Smallest number k such that R(n) is the n-th divisor of k, where R(n) is the n-th Ramanujan prime (A104272).
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0
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11, 34, 116, 246, 752, 708, 4288, 1704, 3492, 4848, 11556, 7620, 28608, 47112, 24048, 21480, 45612, 40860, 54960, 218088, 180684, 121464, 94680, 242100, 269760, 486288, 313488, 249840, 376920, 308280, 738540, 721800, 515340, 1106160, 930960, 935280, 737520
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OFFSET
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2,1
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LINKS
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EXAMPLE
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a(2) = 11 because the divisors of 11 are {1, 11}, and the 2nd divisor of 11 is 11 = A104272(2);
a(3) = 34 because the divisors of 34 are {1, 2, 17, 34}, and the 3rd divisor of 34 is 17 = A104272(3).
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MATHEMATICA
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nn=20; R=Table[0, {nn}]; s=0; Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s<nn, R[[s+1]]=k], {k, Prime[3*nn]}]; R=R+1; t=Table[0, {nn}]; found=1; n=2; While[found < nn, n++; d=Divisors[n]; Do[If[i <= nn && d[[i]] == Part[R, i] && t[[i]]==0, t[[i]]=n; found++], {i, Length[d]}]]; Rest[t] (* Program from T. D. Noe adapted for this sequence - see A104272 and A221647 *)
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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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