OFFSET
1,3
COMMENTS
Note the indexing: the domain starts from 1, but the range includes also zero.
LINKS
MATHEMATICA
Table[If[n < 3, n - 1, Block[{k = #, m = 0}, Times @@ Power @@@ Table[k -= m; k = DeleteCases[k, 0]; {Prime@ Length@ k, m = Min@ k}, Length@ Union@ k]] &@ Catenate[ConstantArray[PrimePi[#1], #2] & @@@ FactorInteger@ #] &@ Floor@ Total@ Flatten@ MapIndexed[#1 2^(#2 - 1) &, Flatten[Table[2^(PrimePi@ #1 - 1), {#2}] & @@@ FactorInteger@ n]]], {n, 67}] (* Michael De Vlieger, Dec 31 2018, after JungHwan Min at A122111 *)
PROG
(PARI)
A064989(n) = {my(f); f = factor(n); if((n>1 && f[1, 1]==2), f[1, 2] = 0); for (i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f)};
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 30 2018
STATUS
approved