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A045252 Numbers whose base-5 expansion contains exactly one 1 and one 4. 1
9, 21, 29, 39, 44, 45, 47, 48, 59, 71, 84, 96, 101, 105, 107, 108, 111, 116, 129, 139, 144, 145, 147, 148, 179, 189, 194, 195, 197, 198, 204, 214, 219, 220, 222, 223, 225, 227, 228, 235, 237, 238, 240, 242, 243, 259, 271, 279, 289 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

d:= 4: # for all terms with up to d base-5 digits.

Res:= NULL;

for m from 0 to 3^(d-2)-1 do

     L:= subs(1=3, convert(3^(d-2)+m, base, 3));

     for i from 0 to d-2 do

       for j from i+1 to d-1 do

         xpos:= subs(i=NULL, j=NULL, [$0..d-1]);

         x:= add(L[i]*5^xpos[i], i=1..d-2);

         Res:= Res, x + 5^i+4*5^j, x+4*5^i+5^j

od od od:

sort([Res]); # Robert Israel, Jan 19 2020

MATHEMATICA

Select[Range[300], DigitCount[#, 5, 1]==DigitCount[#, 5, 4]==1&] (* Harvey P. Dale, May 04 2021 *)

PROG

(MAGMA) [k:k in [1..300]| Multiplicity(Intseq(k, 5), 1) eq 1 and Multiplicity(Intseq(k, 5), 4) eq 1]; // Marius A. Burtea, Jan 20 2020

CROSSREFS

Sequence in context: A339728 A267216 A039289 * A139538 A173460 A110701

Adjacent sequences:  A045249 A045250 A045251 * A045253 A045254 A045255

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified September 22 19:36 EDT 2021. Contains 347608 sequences. (Running on oeis4.)