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A044363
Numbers n such that string 3,1 occurs in the base 10 representation of n but not of n-1.
0
31, 131, 231, 310, 331, 431, 531, 631, 731, 831, 931, 1031, 1131, 1231, 1310, 1331, 1431, 1531, 1631, 1731, 1831, 1931, 2031, 2131, 2231, 2310, 2331, 2431, 2531, 2631, 2731, 2831, 2931, 3031, 3100, 3231, 3310, 3331, 3431
OFFSET
1,1
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {3, 1}]>0, 1, 0], {n, 3500}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 08 2018 *)
CROSSREFS
Sequence in context: A045229 A038475 A141931 * A044744 A167388 A250462
KEYWORD
nonn,base
STATUS
approved