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 A346135 Numbers k such that k and 4k, taken together, contain all digits 1 though 9 at least once. 0
 3942, 4392, 5796, 7956, 11738, 11963, 13196, 13692, 13698, 13724, 13742, 13942, 14237, 14392, 14673, 14693, 15473, 15737, 15873, 15942, 15948, 16473, 17357, 17358, 17381, 17438, 17453, 17458, 17463, 18559, 18592, 19463, 19613, 19631, 19643, 19863, 21369, 21374, 21394, 21439 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The first four members use all the digits 1-9 exactly once. They form the sequence A115929. LINKS Table of n, a(n) for n=1..40. EXAMPLE 3942 and 3942*4=15768 use once all the digits from 1 to 9. 11738 and 11738*4=46952 use all the digits from 1 to 9 with repetitions. MAPLE q:= n-> (s-> is({seq(parse(s[i]), i=1..length(s))}={\$1..9}))(cat("", n, 4*n)): select(q, [\$1..22000])[]; # Alois P. Heinz, Jul 05 2021 MATHEMATICA Select[Range[1000, 99999], Union[IntegerDigits[#], IntegerDigits[4 #]] == {1, 2, 3, 4, 5, 6, 7, 8, 9} &] PROG (Python) def ok(n): return (set(str(n)) | set(str(4*n))) == set("123456789") print(list(filter(ok, range(21440)))) # Michael S. Branicky, Jul 05 2021 (PARI) isok(k) = my(s=setunion(Set(digits(k)), Set(digits(4*k)))); vecmin(s) && (#s == 9); \\ Michel Marcus, Jul 11 2021 CROSSREFS Cf. A115929 (finite subsequence). Sequence in context: A233688 A162859 A115929 * A070185 A059354 A059666 Adjacent sequences: A346132 A346133 A346134 * A346136 A346137 A346138 KEYWORD nonn,base AUTHOR Tanya Khovanova, Jul 05 2021 STATUS approved

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Last modified November 30 21:14 EST 2023. Contains 367462 sequences. (Running on oeis4.)