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Revision History for A065372

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A065372

a(n) = A065371(A065371(n)).
(history; published version)

#13 by Peter Luschny at Sun Nov 21 07:34:04 EST 2021

STATUS

proposed

approved

#12 by Michel Marcus at Sun Nov 21 03:21:50 EST 2021

STATUS

editing

proposed

#11 by Michel Marcus at Sun Nov 21 03:21:46 EST 2021

PROG

(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

STATUS

proposed

editing

#10 by Jean-François Alcover at Sun Nov 21 03:10:16 EST 2021

STATUS

editing

proposed

#9 by Jean-François Alcover at Sun Nov 21 03:10:12 EST 2021

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 *)

STATUS

approved

editing

#8 by N. J. A. Sloane at Thu Jan 12 20:12:56 EST 2017

STATUS

proposed

approved

#7 by Antti Karttunen at Thu Jan 12 18:45:49 EST 2017

STATUS

editing

proposed

#6 by Antti Karttunen at Thu Jan 12 18:41:14 EST 2017

LINKS

Antti Karttunen, <a href="/A065372/b065372.txt">Table of n, a(n) for n = 1..10000</a>

#5 by Antti Karttunen at Thu Jan 12 18:39:49 EST 2017

PROG

(Scheme) (define (A065372 n) (A065371 (A065371 n))) ;; Antti Karttunen, Jan 12 2017

CROSSREFS

Cf. A065371, A065373, A065374.

EXTENSIONS

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

Discussion

Thu Jan 12

18:40

Antti Karttunen: This sequence occurs very commonly as a false positive in equivalence class matches. Thus I extended the data section up to 120 terms, although the b-file will help more.

#4 by Antti Karttunen at Thu Jan 12 18:38:22 EST 2017

DATA

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

STATUS

approved

editing