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A130429 List of all numbers n such that n is equal to the number of 7's in the decimal digits of all numbers <= n. 14

%I #14 May 24 2023 17:19:19

%S 0,9465000000,9471736170,9500000000,9757536170,9965000000,9971736170,

%T 10000000000,19465000000,19471736170,19500000000,19757536170,

%U 19965000000,19971736170,20000000000,29465000000,29471736170

%N List of all numbers n such that n is equal to the number of 7's in the decimal digits of all numbers <= n.

%C A finite sequence with 49 terms.

%H Graeme McRae, May 26 2007, <a href="/A130429/b130429.txt">Table of n, a(n) for n = 1..49</a> (full sequence)

%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(5)=9757536170 because the number of 7's in the decimal digits of the numbers from 0 to 9757536170 is 9757536170 and this is the 5th such number.

%Y Cf. A014778 for proof these sequences are finite; Also A101639, A101640, A101641, A130427, A130428, A130430, A130431; Cf. A130432 for the number of numbers in these sequences.

%K base,fini,full,nonn

%O 1,2

%A _Graeme McRae_, May 26 2007

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Last modified July 13 20:28 EDT 2024. Contains 374288 sequences. (Running on oeis4.)