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A117103
a(n) is the least odd composite number m such that nextprime(p*m) > p*nextprime(m) where p is the n-th prime.
1
27, 39, 105, 279, 629, 597, 1661, 1875, 3777, 13961, 15491, 33585, 87401, 11445, 28877, 113451, 265115, 146189, 584705, 668525, 1370667, 1582581, 1471865, 2193351, 2932901, 3832635, 3571617, 3617721, 15131459, 31245831, 11442269
OFFSET
1,1
COMMENTS
If k is prime then nextprime(k)=k.
LINKS
EXAMPLE
For n=1, p=2, the least odd composite m such that f(2*m) > 2*f(m) is 27=a(1).
PROG
(PARI) f(n)=nextprime(n); g(n, a)=for(i=1, a, if(f(n*i)>f(n)*f(i) && !isprime(i) && Mod(i, 2)!=0, return(i))); forprime (i=1, 150, print1(g(i, 500000000), ", "))
CROSSREFS
Sequence in context: A181489 A369251 A369252 * A217008 A372443 A355903
KEYWORD
nonn
AUTHOR
Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006
EXTENSIONS
a(26)-a(30) from Zak Seidov, May 15 2007
a(31)-a(32) from Ray Chandler, May 30 2007
STATUS
approved