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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A043208 Numbers k such that 4 and 7 occur juxtaposed in the base-9 representation of k but not of k-1. 0
43, 67, 124, 148, 205, 229, 286, 310, 367, 387, 448, 472, 529, 553, 603, 634, 691, 715, 772, 796, 853, 877, 934, 958, 1015, 1039, 1096, 1116, 1177, 1201, 1258, 1282, 1332, 1363, 1420, 1444, 1501, 1525, 1582, 1606, 1663, 1687 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {4, 7}]>0 || SequenceCount[IntegerDigits[n, 9], {7, 4}]>0, 1, 0], {n, 2000}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 28 2018 *)
CROSSREFS
Cf. A007095.
Sequence in context: A139917 A146334 A039385 * A043988 A139499 A201688
KEYWORD
nonn,base
AUTHOR
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 20 07:46 EDT 2024. Contains 374442 sequences. (Running on oeis4.)