The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A134193 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A134193

a(1) = 1; for n>1, a(n) = the smallest positive integer not occurring among the exponents in the prime-factorization of n.
(history; published version)

#13 by N. J. A. Sloane at Sat Jul 29 19:19:48 EDT 2017

STATUS

proposed

approved

#12 by Michel Marcus at Fri Jul 28 12:10:26 EDT 2017

STATUS

editing

proposed

#11 by Michel Marcus at Fri Jul 28 12:10:22 EDT 2017

PROG

(PARI) a(n) = if (n==1, 1, my(f=factor(n)); ve = vecsort(f[, 2], , 8); k = 1; while(vecsearch(ve, k), k++); k; ); \\ Michel Marcus, Jul 28 2017

STATUS

proposed

editing

#10 by Antti Karttunen at Fri Jul 28 12:00:15 EDT 2017

STATUS

editing

proposed

#9 by Antti Karttunen at Fri Jul 28 11:59:08 EDT 2017

LINKS

Antti Karttunen, <a href="/A134193/b134193.txt">Table of n, a(n) for n = 1..10000</a>

<a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a>

FORMULA

a(n) = A257993(A181819(n)). - Antti Karttunen, Jul 28 2017

PROG

(Scheme) (define (A134193 n) (A257993 (A181819 n))) ;; Antti Karttunen, Jul 28 2017

CROSSREFS

Cf. A136567, A181819, A257993.

STATUS

approved

editing

#8 by Jon E. Schoenfield at Wed Sep 16 13:42:31 EDT 2015

STATUS

editing

approved

#7 by Jon E. Schoenfield at Wed Sep 16 13:42:30 EDT 2015

MATHEMATICA

Table[Complement[Range[n], Table[FactorInteger[n][[i, 2]], {i, 1, Length[FactorInteger[n]]}]][[1]], {n, 2, 120}] - _(* _Stefan Steinerberger_, Jan 21 2008 *)

STATUS

approved

editing

#6 by Charles R Greathouse IV at Wed Apr 09 10:12:26 EDT 2014

AUTHOR

Leroy Quet , Jan 13 2008

Discussion

Wed Apr 09

10:12

OEIS Server: https://oeis.org/edit/global/2145

#5 by N. J. A. Sloane at Wed Feb 05 20:18:43 EST 2014

AUTHOR

_Leroy Quet _ Jan 13 2008

Discussion

Wed Feb 05

20:18

OEIS Server: https://oeis.org/edit/global/2118

#4 by Russ Cox at Fri Mar 30 18:49:46 EDT 2012

MATHEMATICA

Table[Complement[Range[n], Table[FactorInteger[n][[i, 2]], {i, 1, Length[FactorInteger[n]]}]][[1]], {n, 2, 120}] - _Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), _, Jan 21 2008

EXTENSIONS

More terms from _Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), _, Jan 21 2008

Discussion

Fri Mar 30

18:49

OEIS Server: https://oeis.org/edit/global/238