OFFSET
1,1
COMMENTS
The 5th term a(5) has 268 digits and is too long to display in data section.
The 7th term a(7) in the sequence has 823 digits.
a(8) has 2030 digits; a(9) has 2264 digits (these are not included in b-file).
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..7
EXAMPLE
a(1)= 19: n= 2: (2*n)!- n!^2-1= 19 which is prime.
a(2)= 683: n= 3: (2*n)!- n!^2-1= 683 which is prime.
MAPLE
KD := proc() local a; a:=(2*n)!-n!^2-1; if isprime(a) then RETURN (a); fi; end: seq(KD(), n=1..200);
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, Dec 03 2013
STATUS
approved