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A257223
Numbers that have at least one divisor containing the digit 6 in base 10.
7
6, 12, 16, 18, 24, 26, 30, 32, 36, 42, 46, 48, 52, 54, 56, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 72, 76, 78, 80, 84, 86, 90, 92, 96, 102, 104, 106, 108, 112, 114, 116, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 144, 146, 150, 152, 156, 160, 161, 162
OFFSET
1,1
COMMENTS
Numbers k whose concatenation of divisors A037278(k), A176558(k), A243360(k) or A256824(k) contains a digit 6.
A011536 (numbers that contain a 6) is a subsequence. - Michel Marcus, May 25 2015
FORMULA
a(n) ~ n.
EXAMPLE
18 is in sequence because the list of divisors of 18: (1, 2, 3, 6, 9, 18) contains digit 6.
MATHEMATICA
Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 6] > 0 &]
Select[Range[200], Count[Flatten[IntegerDigits/@Divisors[#]], 6]>0&] (* Harvey P. Dale, Nov 05 2021 *)
PROG
(Magma) [n: n in [1..1000] | [6] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))]
(PARI) is(n)=fordiv(n, d, if(setsearch(Set(digits(d)), 6), return(1))); 0
CROSSREFS
Cf. similar sequences with another digit: A209932 (0), A000027 (1), A257219 (2), A257220 (3), A257221 (4), A257222 (5), A257224 (7), A257225 (8), A257226 (9).
Sequence in context: A315623 A315624 A013637 * A092455 A315625 A315626
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, May 05 2015
EXTENSIONS
Mathematica and PARI programs with assistance from Michael De Vlieger and Charles R Greathouse IV, respectively.
STATUS
approved