The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A043211 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A043211

Numbers k such that 5 and 7 occur juxtaposed in the base-9 representation of k but not of k-1.
(history; published version)

#11 by Alois P. Heinz at Mon Aug 23 06:36:33 EDT 2021

STATUS

reviewed

approved

#10 by Michel Marcus at Mon Aug 23 02:04:56 EDT 2021

STATUS

proposed

reviewed

#9 by Jon E. Schoenfield at Mon Aug 23 01:20:00 EDT 2021

STATUS

editing

proposed

#8 by Jon E. Schoenfield at Mon Aug 23 01:19:58 EDT 2021

NAME

Numbers n k such that 5 and 7 occur juxtaposed in the base -9 representation of n k but not of nk-1.

CROSSREFS

Cf. A007095.

STATUS

approved

editing

#7 by Harvey P. Dale at Thu Nov 02 18:14:45 EDT 2017

STATUS

editing

approved

#6 by Harvey P. Dale at Thu Nov 02 18:14:41 EDT 2017

MATHEMATICA

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {5, 7}]>0 || SequenceCount[IntegerDigits[n, 9], {7, 5}]>0, 1, 0], {n, 1700}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 02 2017 *)

STATUS

approved

editing

#5 by Russ Cox at Fri Mar 30 18:56:34 EDT 2012

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu)

Clark Kimberling

Discussion

Fri Mar 30

18:56

OEIS Server: https://oeis.org/edit/global/285

#4 by N. J. A. Sloane at Fri May 11 03:00:00 EDT 2007

NAME

Numbers n such that 5 and 7 occur juxtaposed in the base 9 representation of n but not of n-1.

KEYWORD

nonn,base,new

#3 by N. J. A. Sloane at Sat Sep 13 03:00:00 EDT 2003

KEYWORD

nonn,base,new

AUTHOR

Clark Kimberling, (ck6(AT)evansville.edu)

#2 by N. J. A. Sloane at Fri May 16 03:00:00 EDT 2003

NAME

5 and 7 occur juxtaposed in the base 9 representation of n, but not of n-1.

KEYWORD

nonn,base,new

AUTHOR

Clark Kimberling, ck6@cedar.(AT)evansville.edu