A043498 Numbers having two 2's in base 10.

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

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

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

Adjacent sequences: A043495 A043496 A043497 * A043499 A043500 A043501

Keyword

nonn,base

Author

Clark Kimberling

Status

approved