login
A032811
Numbers whose set of base-11 digits is {2,3}.
1
2, 3, 24, 25, 35, 36, 266, 267, 277, 278, 387, 388, 398, 399, 2928, 2929, 2939, 2940, 3049, 3050, 3060, 3061, 4259, 4260, 4270, 4271, 4380, 4381, 4391, 4392, 32210, 32211, 32221, 32222, 32331, 32332, 32342, 32343, 33541, 33542, 33552, 33553, 33662, 33663
OFFSET
1,1
LINKS
Vincenzo Librandi and Bruno Berselli, Table of n, a(n) for n = 1..1000 (first 200 terms from Vincenzo Librandi).
FORMULA
a(1)=2, a(2)=3; a(n) = 11*a(floor(n/2))+2 for n odd, otherwise a(n) = 11*a(floor((n-1)/2))+3. - Bruno Berselli, May 28 2012
MATHEMATICA
fQ[n_]:=Union@Join[{2, 3}, IntegerDigits[n, 11]]=={2, 3}; Select[Range[0, 60000], fQ] (* Vincenzo Librandi, May 25 2012 *)
Table[FromDigits[#, 11]&/@Tuples[{2, 3}, n], {n, 5}]//Flatten (* Harvey P. Dale, Sep 14 2018 *)
PROG
(PARI) {for(vv=1, 44,
bvv=binary(vv+1);
texp=0; btb=0;
forstep(i=length(bvv)-1, 1, -1, btb=btb+(2+bvv[i+1])*11^texp; texp++);
print1(btb, ", "))} \\ Douglas Latimer, May 17 2012
(Maxima) a[1]:2$ a[2]:3$ a[n]:= if oddp(n) then 11*a[floor(n/2)]+2 else 11*a[floor((n-1)/2)]+3$ makelist(a[n], n, 1, 44); \\ Bruno Berselli, May 28 2012
(Magma) [n: n in [1..33663] | Set(IntegerToSequence(n, 11)) subset {2, 3}]; // Bruno Berselli, May 28 2012
CROSSREFS
Sequence in context: A343206 A055067 A037319 * A092049 A257789 A336616
KEYWORD
nonn,base,easy
EXTENSIONS
More terms from Douglas Latimer, May 17 2012
STATUS
approved