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A235693 Semiprimes which have one or more occurrences of exactly five different digits. 3
10237, 10238, 10239, 10249, 10265, 10279, 10294, 10297, 10327, 10342, 10345, 10347, 10349, 10358, 10367, 10378, 10379, 10389, 10394, 10397, 10423, 10435, 10462, 10473, 10483, 10489, 10493, 10495, 10497, 10523, 10537, 10543, 10546, 10547, 10562, 10573, 10579 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The first term having a repeated digit is 100235.

The first term that is a square is 12769. - Robert Israel, Jul 06 2018

LINKS

Robert Israel, Table of n, a(n) for n = 1..6240

MAPLE

# to get all terms with 5 digits S:= combinat:-choose([$0..9], 5):

f:= proc(x) local s, L;

      L:= convert(x, base, 5);      if nops(L) < 5 then L:= [op(L), 0$(5-nops(L))] fi;      if nops(convert(L, set))<5 then return NULL fi;

      op(select(t -> t > 10^4 and numtheory:-bigomega(t)=2, map(s -> add(s[L[i]+1]*10^(i-1), i=1..5), S)))

end proc:

sort(map(f, [$1..5^5-1])); # Robert Israel, Jul 06 2018

MATHEMATICA

Select[Range[10000, 11000], PrimeOmega[#]==2&&Count[DigitCount[#], 0]==5&] (* Harvey P. Dale, Apr 08 2015 *)

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(15000); s=[]; for(n=1, #b, if(#vecsort(eval(Vec(Str(b[n]))), , 8)==5, s=concat(s, b[n]))); s

CROSSREFS

Cf. A235690-A235692, A235694-A235696.

Cf. A235154-A235161.

Sequence in context: A183743 A236743 A031987 * A247948 A254563 A074671

Adjacent sequences:  A235690 A235691 A235692 * A235694 A235695 A235696

KEYWORD

nonn,base

AUTHOR

Colin Barker, Jan 14 2014

STATUS

approved

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Last modified July 27 11:45 EDT 2021. Contains 346304 sequences. (Running on oeis4.)