A280701 a(n) = n - A280704(n).

0, 1, 2, 3, 4, 5, 6, 1, 8, 1, 10, 1, 12, 1, 14, 11, 16, 1, 18, 1, 20, 1, 22, 1, 24, 1, 14, 19, 28, 1, 30, 1, 16, 1, 34, 29, 36, 1, 20, 27, 40, 1, 42, 1, 22, 1, 46, 1, 48, 49, 26, 51, 52, 1, 54, 51, 28, 1, 58, 1, 60, 1, 32, 57, 64, 65, 66, 1, 34, 1, 70, 1, 72, 1, 38, 51, 76, 1, 78, 1, 40, 1, 82, 1, 84, 1, 44, 59, 88, 1, 90, 1, 46

Offset

1,3

Comments

Questions: Are all terms nonnegative? Where do ones occur?

Links

Antti Karttunen, Table of n, a(n) for n = 1..13098

Formula

a(n) = n - A280704(n) = n - (A250469(n)/gcd(A003961(n),A250469(n))).

Mathematica

f[n_] := f[n] = Which[n == 1, 1, PrimeQ@ n, NextPrime@ n, True, Times @@ Replace[FactorInteger[n], {p_, e_} :> f[p]^e, 1]]; g[n_] := If[n == 1, 0, PrimePi@ FactorInteger[n][[1, 1]]]; Function[s, MapIndexed[ Function[t, First@ #2 - t/GCD[t, f@ First@ #2]][Lookup[s, g[First@ #2] + 1][[#1]] - Boole[First@ #2 == 1]] &, #] &@ Map[Position[Lookup[s, g@ #], #][[1, 1]] &, Range@ 120]]@ PositionIndex@ Array[g, 10^4] (* Michael De Vlieger, Mar 08 2017, Version 10 *)

Prog

(Scheme) (define (A280701 n) (- n (A280704 n)))

Crossrefs

Cf. A003961, A250469, A280702, A280704.

Sequence in context: A138776 A339738 A364500 * A064830 A355582 A160377

Adjacent sequences: A280698 A280699 A280700 * A280702 A280703 A280704

Keyword

nonn

Author

Antti Karttunen, Mar 08 2017

Status

approved