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A257225 Numbers n that have at least one divisor containing the digit 8 in base 10. 7
8, 16, 18, 24, 28, 32, 36, 38, 40, 48, 54, 56, 58, 64, 68, 72, 76, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 96, 98, 104, 108, 112, 114, 116, 118, 120, 126, 128, 136, 138, 140, 144, 148, 152, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers n whose concatenation of divisors A037278(n), A176558(n), A243360(n) or A256824(n) contains a digit 8.

A011538 (numbers that contain an 8) is a subsequence. - Michel Marcus, May 19 2015

LINKS

Table of n, a(n) for n=1..58.

FORMULA

a(n) ~ n.

EXAMPLE

18 is in sequence because the list of divisors of 18: (1, 2, 3, 6, 9, 18) contains digit 8.

MAPLE

select(t -> has(map(convert, numtheory:-divisors(t), base, 10), 8), [$1..200]); # Robert Israel, May 14 2015

MATHEMATICA

Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 8] > 0 &]

PROG

(MAGMA) [n: n in [1..1000] | [8] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))]

(PARI) is(n)=fordiv(n, d, if(setsearch(Set(digits(d)), 8), return(1))); 0

CROSSREFS

Cf. A037278, A176558, A243360, A256824.

Cf. similar sequences with another digit: A209932 (0), A000027 (1), A257219 (2), A257220 (3), A257221 (4), A257222 (5), A257223 (6), A257224 (7), A257226 (9).

Sequence in context: A328189 A101766 A140270 * A092456 A232724 A260409

Adjacent sequences:  A257222 A257223 A257224 * A257226 A257227 A257228

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, May 07 2015

EXTENSIONS

Programs MATHEMATICA and PARI with assistance by Michael De Vlieger and Charles R Greathouse IV respectively.

STATUS

approved

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Last modified July 8 00:40 EDT 2020. Contains 335502 sequences. (Running on oeis4.)