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%I #35 Jul 15 2023 18:54:04
%S 2,3,22,23,32,33,222,223,232,233,322,323,332,333,2222,2223,2232,2233,
%T 2322,2323,2332,2333,3222,3223,3232,3233,3322,3323,3332,3333,22222,
%U 22223,22232,22233,22322,22323,22332,22333,23222,23223
%N Numbers using only digits 2 and 3.
%C Identical to A007931 with substitution of digits 2 -> 3, 1 -> 2, i.e., application of the function A048379 or A256079(n) = n + A002275(A055642(n)). - _M. F. Hasler_, Mar 21 2015
%H Vincenzo Librandi, <a href="/A032810/b032810.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>.
%F a(n) = f(n+1, 0) with f(n, x) = if n=1 then A004086(x) else f(floor(n/2), 10*x + 2 + n mod 2). - _Reinhard Zumkeller_, Sep 06 2008
%F a(n) is Theta(n^(log_2 10)); there are about n^(log_10 2) members of this sequence up to n. - _Charles R Greathouse IV_, Mar 18 2010
%F a(n) = A007931(n) + A002275(A000523(n+1)). A055642(a(n)) = A000523(n+1). - _M. F. Hasler_, Mar 21 2015
%t Flatten[Table[FromDigits[#,10]&/@Tuples[{2,3},n],{n,5}]] (* _Vincenzo Librandi_, May 27 2012 *)
%o (Magma) [n: n in [1..24000] | Set(Intseq(n)) subset {2, 3}]; // _Vincenzo Librandi_, May 27 2012
%o (Magma) [n eq 1 select 2 else IsOdd(n) select 10*Self(Floor(n/2))+2 else Self(n-1)+1: n in [1..40]]; // _Bruno Berselli_, May 27 2012
%o (Haskell)
%o a032810 = f 0 . (+ 1) where
%o f y 1 = a004086 y
%o f y x = f (10 * y + m + 2) x' where (x', m) = divMod x 2
%o -- _Reinhard Zumkeller_, Mar 18 2015
%o (PARI) A032810(n)=vector(#n=binary(n+1)[2..-1],i,10^(#n-i))*n~+10^#n\9*2 \\ _M. F. Hasler_, Mar 26 2015
%o (Python)
%o def A032810(n): return int(bin(n+1)[3:])+(10**((n+1).bit_length()-1)-1<<1)//9 # _Chai Wah Wu_, Jul 15 2023
%Y Cf. A020458, A143967, A248907 (permutation).
%Y Cf. A032804-A032816 (in other bases), A007088 (digits 0 & 1), A007931 (digits 1 & 2), A032834 (digits 3 & 4), A256290 (digits 4 & 5), A256291 (digits 5 & 6), A256292 (digits 6 & 7), A256340 (digits 7 & 8), A256341 (digits 8 & 9).
%K nonn,base,easy
%O 1,1
%A _Clark Kimberling_
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