A021097 -id:A021097 - cp's OEIS frontend

A351474 Numbers m such that the largest digit in the decimal expansion of 1/m is 8.

7, 12, 14, 26, 28, 35, 48, 54, 55, 56, 63, 65, 70, 72, 78, 79, 93, 117, 120, 123, 125, 128, 140, 175, 176, 186, 192, 195, 205, 224, 239, 259, 260, 264, 280, 296, 312, 318, 328, 350, 372, 416, 432, 438, 448, 465, 480, 540, 542, 546, 548, 550, 555, 560, 572, 584, 594, 630, 632, 650, 675

Offset: 1

Bernard Schott and Robert G. Wilson v, Feb 19 2022

If k is a term, 10*k is also a term. First few primitive terms are 7, 12, 14, 26, 28, 35, 48, 54, 55, 56, 63, 65, 72, ...

The seven primes up to 2.7*10^8 are 7, 79, 239, 62003, 538987, 35121409, 265371653 (see comments in A333237, example section and Crossrefs).

			As 1/7 = 0.142857142857142857..., 7 is a term.
As 1/26 = 0.0384615384615384615..., 26 is another term.

Index entries for sequences related to decimal expansion of 1/n.

Similar with largest digit k: A333402 (k=1), A341383 (k=2), A350814 (k=3), A351470 (k=4), A351471 (k=5), A351472 (k=6), A351473 (k=7), this sequence (k=8), A333237 (k=9).
Cf. A333236.
Decimal expansion of: A020806 (1/7), A021058 (1/54), A021060 (1/56), A021067 (1/63), A021069 (1/65), A021083 (1/79), A021097 (1/93).

f[n_] := Union[ Flatten[ RealDigits[ 1/n][[1]] ]]; Select[Range@1500000, Max@ f@# == 8 &]

isok(m) = my(m2=valuation(m, 2), m5=valuation(m, 5)); vecmax(digits(floor(10^(max(m2,m5) + znorder(Mod(10, m/2^m2/5^m5))+1)/m))) == 8; \\ Michel Marcus, Feb 26 2022

from itertools import count, islice
from sympy import multiplicity, n_order
def A351474_gen(startvalue=1): # generator of terms >= startvalue
    for a in count(max(startvalue,1)):
        m2, m5 = (~a&a-1).bit_length(), multiplicity(5,a)
        k, m = 10**max(m2,m5), 10**n_order(10,a//(1<A351474_list = list(islice(A351474_gen(),20)) # Chai Wah Wu, May 02 2023

A333236(a(n)) = 8.

A021934 Decimal expansion of 1/930.

Original entry on oeis.org

0, 0, 1, 0, 7, 5, 2, 6, 8, 8, 1, 7, 2, 0, 4, 3, 0, 1, 0, 7, 5, 2, 6, 8, 8, 1, 7, 2, 0, 4, 3, 0, 1, 0, 7, 5, 2, 6, 8, 8, 1, 7, 2, 0, 4, 3, 0, 1, 0, 7, 5, 2, 6, 8, 8, 1, 7, 2, 0, 4, 3, 0, 1, 0, 7, 5, 2, 6, 8, 8, 1, 7, 2, 0, 4, 3, 0, 1, 0, 7, 5, 2, 6, 8, 8, 1, 7, 2, 0, 4, 3, 0, 1, 0, 7, 5, 2, 6, 8

Offset: 0

N. J. A. Sloane

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,1).

Join[{0,0},RealDigits[1/930,10,120][[1]]] (* Harvey P. Dale, May 15 2023 *)

A021097 shifted right. [From R. J. Mathar, Oct 25 2008]

cp's OEIS Frontend

A351474 Numbers m such that the largest digit in the decimal expansion of 1/m is 8.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

PARI

Python

Formula