OFFSET
1,1
EXAMPLE
a(1) = 6 because 6' = 5;
a(2) = 4 because 4' = 4 = 2 * 2;
a(3) = 8 because 8' = 12 = 2 * 2 * 3.
MAPLE
with(numtheory): P:= proc(q) local k, n; for n from 1 to q do for k from 1 to q do
if bigomega(k*add(op(2, p)/op(1, p), p=ifactors(k)[2]))=n then print(k); break; fi;
od; od; end: P(10^9);
MATHEMATICA
ad[1]=0; ad[n_] := n*Total[ (#1[[2]] / #1[[1]] &) /@ FactorInteger[n]]; a[n_] := Block[{k=2}, While[PrimeOmega@ ad[k] != n, k++]; k]; Array[a, 15] (* Giovanni Resta, Mar 22 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Mar 21 2017
EXTENSIONS
a(29)-a(31) from Ray Chandler, Mar 24 2017
a(32)-a(33) from Hans Havermann, Mar 24 2017
a(34)-a(36) from Hans Havermann, Mar 26 2017
a(37)-a(39) from Hans Havermann, May 17 2017
STATUS
approved