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 A331596 Number of distinct prime factors of gcd(A122111(n), A241909(n)). 4
 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,15 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(n) = A001221(A331596(n)) = A001221(gcd(A122111(n), A241909(n))). a(n) = A001222(A331597(n)). MATHEMATICA Array[PrimeNu@ If[# == 1, 1, GCD @@ {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] & @@@ #], Function[t, Times @@ Prime@ Accumulate[If[Length@ t < 2, {0}, Join[{1}, ConstantArray[0, Length@ t - 2], {-1}]] + ReplacePart[t, Map[#1 -> #2 & @@ # &, #]]]]@ ConstantArray[0, Transpose[#][[1, -1]]] &[# /. {p_, e_} /; p > 0 :> {PrimePi@ p, e}]} &@ FactorInteger[#]] &, 105] (* Michael De Vlieger, Jan 24 2020, after JungHwan Min at A122111. *) PROG (PARI) A331596(n) = omega(gcd(A122111(n), A241909(n))); CROSSREFS Cf. A001221, A331596, A335197. Sequence in context: A101428 A307223 A321787 * A023586 A023584 A015182 Adjacent sequences:  A331593 A331594 A331595 * A331597 A331598 A331599 KEYWORD nonn AUTHOR Antti Karttunen, Jan 22 2020 STATUS approved

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Last modified May 15 02:21 EDT 2021. Contains 343909 sequences. (Running on oeis4.)