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A043498
Numbers having two 2's in base 10.
4
22, 122, 202, 212, 220, 221, 223, 224, 225, 226, 227, 228, 229, 232, 242, 252, 262, 272, 282, 292, 322, 422, 522, 622, 722, 822, 922, 1022, 1122, 1202, 1212, 1220, 1221, 1223, 1224, 1225, 1226, 1227, 1228, 1229, 1232, 1242, 1252
OFFSET
1,1
LINKS
MAPLE
q:= n-> numboccur(2, convert(n, base, 10))=2:
select(q, [$2..2222])[]; # Alois P. Heinz, Mar 15 2020
MATHEMATICA
Select[Range[5000], DigitCount[#, 10, 2] == 2 &] (* Vincenzo Librandi, Nov 20 2015 *)
PROG
(PARI) c(k, d, b) = {my(c=0, f); while (k>b-1, f=k-b*(k\b); if (f==d, c++); k\=b); if (k==d, c++); return(c)}
for(n=0, 2000, if(c(n, 2, 10)==2, print1(n, ", "))) \\ Altug Alkan, Nov 20 2015
CROSSREFS
Subsequence of A011532.
Sequence in context: A081931 A156293 A225308 * A108571 A247700 A105776
KEYWORD
nonn,base
STATUS
approved