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”).

A044173
Numbers n such that string 5,0 occurs in the base 7 representation of n but not of n-1.
0
35, 84, 133, 182, 231, 245, 280, 329, 378, 427, 476, 525, 574, 588, 623, 672, 721, 770, 819, 868, 917, 931, 966, 1015, 1064, 1113, 1162, 1211, 1260, 1274, 1309, 1358, 1407, 1456, 1505, 1554, 1603, 1617, 1652, 1701, 1715, 1799
OFFSET
1,1
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {5, 0}]>0, 1, 0], {n, 2000}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 06 2018 *)
CROSSREFS
Sequence in context: A111144 A267555 A201632 * A044554 A156126 A119691
KEYWORD
nonn,base
STATUS
approved