OFFSET
1,1
COMMENTS
The first 2 X 2 prime square of a set of ordered 2 X 2 prime squares begins with 2. Just a 2 X 2 prime square is any 4 consecutive primes arranged in a square formation.
FORMULA
A 2 X 2 ordered prime square is 4 consecutive primes arranged in a square of the form p(4n-3) p(4n-2) p(4n-1) p(4n) where n=1, 2, ... and sides are as follows s1 = p(4n-3) p(4n-2) s2 = p(4n-1) p(4n) s3 = p(4n-3) p(4n-1) s4 = p(4n-2) p(4n).
EXAMPLE
The 4th prime square is
41 43
47 53
s1 = 41+43 = 84
s2 = 47+53 = 100
s3 = 41+47 = 88
s4 = 43+53 = 96
sum = 368
So 368 is the 4th term.
PROG
(PARI) sumsides(n) = { local(x, s1, s2, s3, s4); forstep(x=1, n, 4, s1=prime(x)+ prime(x+1); s2=prime(x+2)+ prime(x+3); s3=prime(x)+ prime(x+2); s4=prime(x+1)+ prime(x+3); print1(s1+s2+s3+s4", ") ) }
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Apr 07 2005
STATUS
approved