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A123386
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Largest difference between successive semiprimes up to 10^n inclusive.
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1
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3, 7, 14, 24, 38, 47, 74, 74, 95, 112, 146, 163, 174
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OFFSET
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1,1
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COMMENTS
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There are 4 semiprimes up to 10^1 {4, 6, 9, 10}. The differences between successive semiprimes are {2, 3, 1}. Thus a(1) = Max[ {2, 3, 1} ] = 3.
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LINKS
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PROG
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(PARI) A001358(prev)={ local(a=prev+1) ; while(bigomega(a)!=2, a++ ; ) ; return(a) ; } A123386(n)={ local(sp1=4, sp2=6, a=2) ; while(sp2<=10^n, a=max(a, sp2-sp1) ; sp1=sp2 ; sp2=A001358(sp1) ; ) ; return(a) ; } { for(n=1, 13, print(A123386(n)) ; ) ; } - 2 more term from R. J. Mathar, Jan 17 2008
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CROSSREFS
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KEYWORD
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hard,more,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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