A105092 - OEIS

A105092

Sum of the sides of ordered 2 prime sided prime triangles.

20, 62, 118, 194, 262, 346, 422, 502, 602, 658, 790, 878, 974, 1066, 1162, 1266, 1378, 1462, 1578, 1658, 1766, 1882, 2030, 2122, 2238, 2338, 2458, 2570, 2662, 2762, 2866, 2986, 3106, 3290, 3406, 3514, 3614, 3698, 3830, 3918, 4022, 4150, 4310, 4430, 4538

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..45.

FORMULA

An ordered 2 prime sided prime triangle is 3 consecutive primes arranged in a triangle of the form p(3n-2) p(3n-1) p(3n ) n=1, 2, .. and sides s1 = p(3n-2) p(3n-1) s2 = p(3n-1) p(3n ) s3 = p(3n-2) p(3n )

EXAMPLE

The first 2 prime sided prime triangle is

3 5

sum of sides = (2+3) + (3+5) + (2+5) = 20 the first entry.

PROG

(PARI) sumsidestri3x3(n) = { local(x, j, s); forstep(x=1, n, 3, s = prime(x)+prime(x+1)+prime(x+2); print1(2*s", ") ) }

CROSSREFS

Sequence in context: A041782 A041784 A276962 * A112144 A007248 A117431

Adjacent sequences: A105089 A105090 A105091 * A105093 A105094 A105095

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Apr 07 2005

STATUS

approved