A044015 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A044015

Numbers k such that 2 and 5 occur juxtaposed in the base-10 representation of k but not of k+1.

25, 52, 125, 152, 225, 259, 325, 352, 425, 452, 529, 552, 625, 652, 725, 752, 825, 852, 925, 952, 1025, 1052, 1125, 1152, 1225, 1259, 1325, 1352, 1425, 1452, 1529, 1552, 1625, 1652, 1725, 1752, 1825, 1852, 1925, 1952, 2025

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..41.

MATHEMATICA

SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {2, 5}]>0 || SequenceCount[ IntegerDigits[n], {5, 2}]>0, 1, 0], {n, 2100}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 14 2017 *)

CROSSREFS

Sequence in context: A199990 A201057 A043235 * A118304 A117472 A146633

Adjacent sequences: A044012 A044013 A044014 * A044016 A044017 A044018

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved