OFFSET
1,1
COMMENTS
Note that -61 = (-1)*61 is not a prime. - N. J. A. Sloane, Nov 13 2020
EXAMPLE
2*(0)^2 - 61 = -61, and 61 is a prime
2*(1)^2 - 61 = -59, and 59 is a prime
PROG
(PARI) is(n)=isprime(abs(n)) && n%2 && issquare((n-61)/2) \\ Charles R Greathouse IV, Sep 13 2016
CROSSREFS
KEYWORD
sign
AUTHOR
Charles Kusniec, Sep 12 2016
EXTENSIONS
More terms from Charles R Greathouse IV, Sep 13 2016
Definition revised by N. J. A. Sloane, Nov 13 2020
STATUS
approved