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A225647
Numbers n such that there are no primes in the open interval from (n^2-1)*sqrt(n^2+1) to (n^2+1)*sqrt(n^2-1).
0
1, 3, 4, 6, 7
OFFSET
1,2
COMMENTS
Sequence is probably complete. a(6), if it exists, is greater than 4 * 10^18. - Charles R Greathouse IV, May 14 2013
PROG
(PARI) is(n)=n==1 || nextprime(sqrtint((n^2+1)*(n^2-1)^2-1)+1) > sqrtint((n^2-1)*(n^2+1)^2-1) \\ Charles R Greathouse IV, May 14 2013
CROSSREFS
Sequence in context: A117986 A248738 A070737 * A135599 A283740 A167161
KEYWORD
nonn
AUTHOR
Gerasimov Sergey, May 11 2013
STATUS
approved