A130432 - OEIS

A130432

For digit n from 1 to 9, a(n) = the number of numbers m such that m is equal to the number of n's in the decimal digits of all numbers <= m.

%I #9 May 24 2023 19:40:07

%S 84,14,36,48,5,72,49,344,9

%N For digit n from 1 to 9, a(n) = the number of numbers m such that m is equal to the number of n's in the decimal digits of all numbers <= m.

%C Note: sequences A101639, A101640 and A101641 are defined so that they exclude 0, so they have 13, 35 and 47 elements, respectively. This sequence counts all the zeros, so elements 2,3,4 of this sequence are 14,36,48.

%H Tanya Khovanova and Gregory Marton, <a href="https://arxiv.org/abs/2305.10357">Archive Labeling Sequences</a>, arXiv:2305.10357 [math.HO], 2023. See p. 4.

%e a(3)=36 because there are 36 numbers m such that m is equal to the number of 3's in the decimal digits of all numbers <= m.

%Y See A014778 for proof that these sequences are finite and also A101639, A101640, A101641, A130427, A130428, A130429, A130430, A130431 for the numbers themselves.

%K base,fini,nonn,full

%O 1,1

%A _Graeme McRae_, May 26 2007