A065372 a(n) = A065371(A065371(n)).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 6, 1, 1, 1, 3, 1, 1, 3, 1, 1, 11, 1, 2, 1, 1, 2, 1, 1, 4, 6, 3, 1, 3, 1, 19, 1, 1, 3, 1, 1, 1, 1, 2, 3, 25, 1, 1, 1, 6, 11, 3, 1, 29, 2, 1, 1, 3, 1, 1, 2, 3, 1, 10, 1, 7, 4, 1, 6, 1, 3, 11, 1, 1, 3, 2, 1, 2, 19, 11, 1, 14, 1, 3, 3, 2, 1, 6, 1, 1, 1, 1, 1, 4, 2, 11, 3, 1, 25, 57, 1, 2, 1, 4, 1, 60, 6, 3, 11, 3, 3, 2, 1

Offset

1,13

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Mathematica

b[n_] := b[n] = If[n == 1, 1, If[PrimeQ[n], n - PrimePi[n], Product[{p, e} = pe; b[p]^e, {pe, FactorInteger[n]}]]];
a[n_] := b[b[n]];
Array[a, 120] (* Jean-François Alcover, Nov 21 2021 *)

Prog

(Scheme) (define (A065372 n) (A065371 (A065371 n))) ;; Antti Karttunen, Jan 12 2017
(PARI) b(n) = my(f=factor(n)); for (k=1, #f~, f[k, 1]-=primepi(f[k, 1])); factorback(f); \\ A065371
a(n) = b(b(n)); \\ Michel Marcus, Nov 21 2021

Crossrefs

Cf. A065371, A065373, A065374.

Sequence in context: A010277 A344764 A359635 * A015137 A368202 A136148

Adjacent sequences: A065369 A065370 A065371 * A065373 A065374 A065375

Keyword

mult,nonn

Author

Reinhard Zumkeller, Nov 01 2001

Extensions

Data section extended to 120 terms by Antti Karttunen, Jan 12 2017

Status

approved