A155185 Primes in A155175.

5, 13, 113, 1741, 5101, 8581, 9941, 21841, 26681, 47741, 82013, 481181, 501001, 1009621, 2356621, 2542513, 3279361, 3723721, 4277813, 7757861, 8124481, 13204661, 25311613, 30772013, 44170601, 48619661, 51521401, 52541501, 54236113, 60731221, 72902813

Offset

1,1

Comments

Hypotenuse C (prime numbers only) 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, ar=a*b/2; s=a+b+c, s-+1 are primes. p=1,q=2,a=3,b=4,c=5=prime,s=12-+1primes, ...

Links

Table of n, a(n) for n=1..31.

Mathematica

lst={}; Do[p=n; q=p+1; a=q^2-p^2; c=q^2+p^2; b=2*p*q; ar=a*b/2; s=a+b+c; If[PrimeQ[s-1]&&PrimeQ[s+1], If[PrimeQ[c], AppendTo[lst, c]]], {n, 8!}]; lst (* corrected by Ray Chandler, Feb 11 2020 *)

Crossrefs

Cf. A020882, A020886, A020884, A020883, A024364, A024406, A155171, A155173, A155174, A155175, A155176, A155177, A155178, A155180, A088483, A001844, A096891, A066885, A099776, A110494, A081589

Sequence in context: A228280 A155175 A376992 * A213129 A004063 A005764

Adjacent sequences: A155182 A155183 A155184 * A155186 A155187 A155188

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jan 21 2009

Extensions

Sequence corrected by Ray Chandler, Feb 11 2020

Status

approved