cp's OEIS Frontend

A263019 If n is the i-th positive integer with digital sum j, then a(n) is the j-th positive integer with digital sum i.

%I A263019 #9 Oct 27 2015 21:22:48
%S A263019 1,10,100,1000,10000,100000,1000000,10000000,100000000,2,11,20,101,
%T A263019 110,200,1001,1010,1100,1000000000,12,21,30,102,111,120,201,210,2000,
%U A263019 10000000000,22,31,40,103,112,121,130,300,10001,100000000000,32,41,50,104,113,122
%N A263019 If n is the i-th positive integer with digital sum j, then a(n) is the j-th positive integer with digital sum i.
%C A263019 Digital sum is given by A007953.
%C A263019 This is a self-inverse permutation of the natural numbers, with fixed points A081927.
%C A263019 A007953(n) = A081927(a(n)) for any n>0.
%C A263019 A081927(n) = A007953(a(n)) for any n>0.
%C A263019 a(A051885(n)) = 10^(n-1) for any n>0.
%C A263019 a(10^(n-1)) = A051885(n) for any n>0.
%H A263019 Paul Tek, <a href="/A263019/b263019.txt">Table of n, a(n) for n = 1..10000</a>
%H A263019 Paul Tek, <a href="/A263019/a263019.pl.txt">PERL program for this sequence</a>
%o A263019 (PARI) a(n) = {j = sumdigits(n); v = vector(n, k, sumdigits(k)); i = #select(x->x==j, v); nb = 0; k = 0; while(nb != j, k++; if (sumdigits(k) == i, nb++)); k;} \\ _Michel Marcus_, Oct 16 2015
%Y A263019 Cf. A007953, A051885, A081927, A254524, A263018.
%K A263019 nonn,base
%O A263019 1,2
%A A263019 _Paul Tek_, Oct 07 2015