A105088 Sum of the sides of ordered 2 X 2 prime squares.

34, 120, 240, 368, 516, 648, 816, 960, 1152, 1320, 1488, 1660, 1856, 2024, 2196, 2388, 2596, 2816, 3004, 3192, 3408, 3576, 3740, 3960, 4188, 4472, 4656, 4840, 5016, 5204, 5388, 5640, 5884, 6076, 6332, 6564, 6756, 6960, 7176, 7452, 7676, 7896, 8124, 8304

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.

Links

Table of n, a(n) for n=1..44.

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

Sequence in context: A173308 A044285 A044666 * A039521 A293039 A216308

Adjacent sequences: A105085 A105086 A105087 * A105089 A105090 A105091

Keyword

easy,nonn

Author

Cino Hilliard, Apr 07 2005

Status

approved