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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)