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 A341383 Numbers m such that the largest digit in the decimal expansion of 1/m is 2. 9
 5, 45, 50, 450, 495, 500, 819, 825, 4500, 4545, 4950, 4995, 5000, 8190, 8250, 8325, 45000, 45045, 45450, 47619, 49500, 49950, 49995, 50000, 81819, 81900, 82500, 83250, 83325, 89109, 450000, 450045, 450450, 454500, 454545, 476190, 495000, 499500, 499950, 499995, 500000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If m is a term, 10*m is also a term. 5 is the only prime up to 2.6*10^8 (comments in A333237). Some subsequences: {45, 4545, 454545, ...}, {45045, 45045045, 45045045045, ...}, {45, 495, 4995, 49995, ...}, {819, 81819, 8181819, ...}, {825, 8325, 83325, 833325...}, ... The subsequence of terms where 1/m has only digits {0,2} is m = 5*A333402 = 5, 45, 50, etc.  A333402 is those t where 1/t has only digits {0,1}, so that 1/(5*t) = 2*(1/t)*(1/10) has digits {0,2}, starting from 1/5 = 0.2.  These m are also A333402/2 of the even terms from A333402, since A333402 (like here) is self-similar in that the multiples of 10, divided by 10, are the sequence itself. - Kevin Ryde, Feb 13 2021 LINKS EXAMPLE As 1/45 = 0.0202020202..., 45 is a term. As 1/825 = 0.0012121212121212...., 825 is a term. As 1/47619 = 0.000021000021000021..., 47619 is a term. As 1/4545045 = 0.000000220019824..., 4545045 is not a term. MATHEMATICA Select[Range[10^5], Max[RealDigits[1/#][[1]]] == 2 &] (* Amiram Eldar, Feb 10 2021 *) PROG (Python) from itertools import count, islice from sympy import n_order, multiplicity def A341383_gen(startvalue=1): # generator of terms >= startvalue     for m in count(max(startvalue, 1)):         m2, m5 = multiplicity(2, m), multiplicity(5, m)         if max(str(10**(max(m2, m5)+n_order(10, m//2**m2//5**m5))//m)) == '2':             yield m A341383_list = list(islice(A341383_gen(), 10)) # Chai Wah Wu, Feb 07 2022 CROSSREFS Cf. A333236. Similar with largest digit k: A333402 (k=1), A333237 (k=9). Subsequence: A093143 \ {1}. Decimal expansion: A021499 (1/495), A021823 (1/819). Sequence in context: A262116 A096763 A345398 * A214711 A216767 A288320 Adjacent sequences:  A341380 A341381 A341382 * A341384 A341385 A341386 KEYWORD nonn,base AUTHOR Bernard Schott, Feb 10 2021 EXTENSIONS Missing terms added by Amiram Eldar, Feb 10 2021 STATUS approved

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Last modified August 10 16:24 EDT 2022. Contains 356039 sequences. (Running on oeis4.)