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 A235690 Semiprimes which have one or more occurrences of exactly two different digits. 9
 10, 14, 15, 21, 25, 26, 34, 35, 38, 39, 46, 49, 51, 57, 58, 62, 65, 69, 74, 82, 85, 86, 87, 91, 93, 94, 95, 115, 118, 119, 121, 122, 133, 141, 155, 161, 166, 177, 202, 221, 226, 262, 299, 303, 323, 334, 335, 339, 355, 377, 393, 411, 422, 445, 446, 447, 454 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The first term having a repeated digit is 115. LINKS EXAMPLE 1000000000010101 is a term because it is made of the digits 0 and 1 and it is the product of the two primes 18463559 and 54160739. MATHEMATICA Select[Range[454], Length@Union@ IntegerDigits[#] == 2 && Total[Last /@ FactorInteger[#]] == 2 &] (* Giovanni Resta, Jan 14 2014 *) PROG (PARI) list(lim)=my(v=List(), t); forprime(p=2, sqrt(lim), t=p; forprime(q=p, lim\t, listput(v, t*q))); vecsort(Vec(v)) \\ From A001358 b=list(10000); s=[]; for(n=1, #b, if(#vecsort(eval(Vec(Str(b[n]))), , 8)==2, s=concat(s, b[n]))); s CROSSREFS Cf. A235691-A235696. Cf. A235154-A235161. Sequence in context: A087247 A307507 A171156 * A271568 A229271 A088711 Adjacent sequences:  A235687 A235688 A235689 * A235691 A235692 A235693 KEYWORD nonn,base AUTHOR Colin Barker, Jan 14 2014 STATUS approved

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Last modified June 17 13:59 EDT 2021. Contains 345083 sequences. (Running on oeis4.)