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A043506
Numbers having two 4's in base 10.
2
44, 144, 244, 344, 404, 414, 424, 434, 440, 441, 442, 443, 445, 446, 447, 448, 449, 454, 464, 474, 484, 494, 544, 644, 744, 844, 944, 1044, 1144, 1244, 1344, 1404, 1414, 1424, 1434, 1440, 1441, 1442, 1443, 1445, 1446, 1447, 1448
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[100000], DigitCount[#, 10, 4] == 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, 4, 10)==2, print1(n, ", "))) \\ Altug Alkan, Nov 20 2015
CROSSREFS
Cf. A043498.
Subsequence of A011534.
Sequence in context: A358818 A183642 A183634 * A044376 A102438 A044757
KEYWORD
nonn,base
STATUS
approved