OFFSET
1,2
COMMENTS
LINKS
Jean-François Alcover, Table of n, a(n) for n = 1..167
MATHEMATICA
pMax = 19; smoothMax = 10^15; smoothNumbers[p_?PrimeQ, max_] := Module[{a, aa, k, pp, iter}, k = PrimePi[p]; aa = Array[a, k]; pp = Prime[Range[k]]; iter = Table[{a[j], 0, PowerExpand@Log[pp[[j]], max/Times @@ (Take[pp, j - 1]^Take[aa, j - 1])]}, {j, 1, k}]; Table[Times @@ (pp^aa), Sequence @@ iter // Evaluate] // Flatten // Sort]; Select[(Sqrt[1 + 4*smoothNumbers[pMax, smoothMax]] - 1)/2, IntegerQ]
CROSSREFS
KEYWORD
fini,full,nonn
AUTHOR
Jean-François Alcover, Nov 14 2016
STATUS
approved