OFFSET
1,3
MATHEMATICA
dec[v_, w_] := If[v == 1, Sow@w, dec[v/#, Append[w, #]] & /@ Select[Rest@ Divisors@ v, # <= w[[-1]] &]]; mul[n_] := Reap[dec[n/#, {#}] & /@ Rest@ Divisors@n][[2, 1]]; ev[e_] := Times @@ (Prime[ Range@ Length@ e]^e); a[n_] := If[n == 1, 1, Min[ev /@ (mul[ DivisorSigma[0, n!]] - 1)]/n]; Array[a, 24] (* Giovanni Resta, Jul 29 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Jul 29 2016
EXTENSIONS
a(12)-a(24) from Giovanni Resta, Jul 29 2016
STATUS
approved