OFFSET
1,1
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
MATHEMATICA
With[{j = 0, k = 7}, Position[Partition[Array[Boole[Total@ {SequenceCount[#, {j, k}], SequenceCount[#, {k, j}]} > 0] &@ IntegerDigits[#] &, 2100], 2, 1], {1, 0}][[All, 1]]] (* Michael De Vlieger, Aug 27 2021 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved