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A368549
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a(n) is the least k such that the greatest prime less than n*k is less than n times the greatest prime < k.
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1
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8, 12, 24, 24, 20, 18, 38, 14, 54, 30, 138, 98, 152, 90, 84, 80, 240, 504, 68, 200, 354, 854, 224, 1020, 230, 180, 510, 542, 524, 522, 368, 968, 578, 1098, 1130, 3462, 744, 504, 1218, 1988, 468, 938, 812, 758, 684, 4002, 2592, 642, 3120, 4458, 2958, 3272, 4920, 572, 5060, 3300, 14490, 3188, 6012
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OFFSET
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2,1
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COMMENTS
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a(n) = p + 1 where p is the first prime such that there are no primes between n*p and n*(p+1).
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LINKS
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EXAMPLE
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a(4) = 24 because the greatest prime < 24 is 23 and the greatest prime < 4*24 is 89 < 4*23.
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MAPLE
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f:= proc(n) local p;
p:= 1;
do
p:= nextprime(p);
if not ormap(isprime, [$ (n*p+1) .. (n*p+n-1)]) then return p+1 fi
od
end proc:
map(f, [$2..100]);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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