A358003 - OEIS

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A358003

Least composite number k such that there are n digits in the intersection of the sets of digits of k and of the juxtaposition of prime factors of k (apart from multiplicity).

4, 12, 95, 132, 1972, 12305, 104392, 1026934, 10298746, 102367895, 1023485967

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OFFSET

0,1

LINKS

Table of n, a(n) for n=0..10.

EXAMPLE

a(0) = 4 = (2*2) there are 0 digits in the intersection of {4} and {2}, and no lesser composite with this property exists.

a(1) = 12 = (2*2 * 3)

a(2) = 95 = (5 * 19)

a(3) = 132 = (2*2 * 3 * 11)

a(4) = 1972 = (2*2 * 17 * 29)

a(5) = 12305 = (5 * 23 * 107)

a(6) = 104392 = (2*2*2 * 13049)

a(7) = 1026934 = (2 * 463 * 1109)

a(8) = 10298746 = (2 * 1069 * 4817)

a(9) = 102367895 = (5 * 7 * 109 * 26833)

a(10) = 1023485967 = (3*3 * 7 * 16245809)

PROG

(PARI) card(k)=my(u=Set(digits(k)), m=factor(k), v=[]); for(i=1, #m~, v=setunion(v, Set(digits(m[i, 1])))); #setintersect(u, v)

a(n)=if(n>10, return(0)); forcomposite(k=10^(n-1), , x=card(k); if(x==n, return(k)))

CROSSREFS

Sequence in context: A009629 A203110 A197919 * A009651 A074930 A287596

Adjacent sequences: A358000 A358001 A358002 * A358004 A358005 A358006

KEYWORD

nonn,base,fini,full

AUTHOR

Jean-Marc Rebert, Oct 24 2022

STATUS

approved