A155176 - OEIS

A155176

Perimeter s/6 (divided by 6) of primitive Pythagorean triangles such that perimeters are Averages of twin prime pairs, q=p+1, a=q^2-p^2, c=q^2+p^2, b=2*p*q, s=a+b+c, s-+1 are primes.

2, 5, 40, 77, 287, 590, 1335, 1717, 2882, 3337, 3927, 4030, 6902, 7315, 7740, 8932, 15965, 20592, 26070, 27405, 34277, 34580, 40920, 50692, 92132, 96647, 113575, 139690, 160557, 167167, 220225, 237407, 279720, 300832, 310765, 336777, 389895

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

OFFSET

1,1

COMMENTS

p=1,q=2,a=3,b=4,c=5,s=12-+1primes, ...

LINKS

Table of n, a(n) for n=1..37.

MATHEMATICA

lst={}; Do[p=n; q=p+1; a=q^2-p^2; c=q^2+p^2; b=2*p*q; s=a+b+c; If[PrimeQ[s-1]&&PrimeQ[s+1], AppendTo[lst, s/6]], {n, 8!}]; lst

CROSSREFS

Cf. A020882, A020886, A020884, A020883, A024364, A024406, A155171, A155173, A155174, A155175

Sequence in context: A109003 A120031 A110066 * A127974 A012801 A183910

Adjacent sequences: A155173 A155174 A155175 * A155177 A155178 A155179

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jan 21 2009

STATUS

approved