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A257220 Numbers n that have at least one divisor containing the digit 3 in base 10. 8
3, 6, 9, 12, 13, 15, 18, 21, 23, 24, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 42, 43, 45, 46, 48, 51, 52, 53, 54, 57, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 73, 74, 75, 76, 78, 81, 83, 84, 86, 87, 90, 91, 92, 93, 96, 99, 102, 103, 104, 105, 106, 108 (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 3.

Sequences of numbers n whose concatenation of divisors contains a digit k in base 10 for 0 <= k <= 9: A209932 for k = 0, A000027 for k = 1, A257219 for k = 2, A257220 for k = 3, A257221 for k = 4, A257222 for k = 5, A257223 for k = 6, A257224 for k = 7, A257225 for k = 8, A257226 for k = 9.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

FORMULA

a(n) ~ n. - Charles R Greathouse IV, Apr 30 2015

EXAMPLE

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

MATHEMATICA

Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 3] > 0 &] (* Michael De Vlieger, Apr 20 2015 *)

PROG

(MAGMA) [n: n in [1..1000] | [3] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))]

(PARI) is(n)=fordiv(n, d, if(setsearch(Set(digits(d)), 3), return(1))); 0 \\ Charles R Greathouse IV, Apr 30 2015

CROSSREFS

Cf. A037278, A176558, A243360, A256824.

Sequence in context: A297567 A285402 A153403 * A092452 A230215 A120688

Adjacent sequences:  A257217 A257218 A257219 * A257221 A257222 A257223

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Apr 20 2015

STATUS

approved

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Last modified May 26 18:08 EDT 2020. Contains 334630 sequences. (Running on oeis4.)