OFFSET
1,1
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {1, 4}]> 0 || SequenceCount[IntegerDigits[n], {4, 1}]>0, 1, 0], {n, 2100}], {1, 0}] [[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 01 2019 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved