login

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”).

A043196
Numbers k such that 2 and 4 occur juxtaposed in the base-9 representation of k but not of k-1.
0
22, 38, 103, 119, 184, 198, 265, 281, 342, 362, 427, 443, 508, 524, 589, 605, 670, 686, 751, 767, 832, 848, 913, 927, 994, 1010, 1071, 1091, 1156, 1172, 1237, 1253, 1318, 1334, 1399, 1415, 1480, 1496, 1561, 1577, 1642, 1656
OFFSET
1,1
MATHEMATICA
Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {2, 4}]>0||SequenceCount[IntegerDigits[n, 9], {4, 2}]>0, 1, 0], {n, 2000}], {0, 1}]][[2]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10.1 *) (* Harvey P. Dale, Apr 08 2015 *)
CROSSREFS
Cf. A007095.
Sequence in context: A057836 A078612 A039373 * A043976 A131196 A075217
KEYWORD
nonn,base
STATUS
approved