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A155171 Numbers p 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. 10
1, 2, 7, 10, 20, 29, 44, 50, 65, 70, 76, 77, 101, 104, 107, 115, 154, 175, 197, 202, 226, 227, 247, 275, 371, 380, 412, 457, 490, 500, 574, 596, 647, 671, 682, 710, 764, 829, 926, 1052, 1085, 1102, 1127, 1186, 1204, 1205, 1225, 1256, 1280, 1324, 1325, 1331 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..52.

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, n]], {n, 8!}]; lst

CROSSREFS

Cf. A020882, A020886, A020884, A020883, A024364, A024406

Sequence in context: A152211 A309805 A125852 * A049830 A270879 A022302

Adjacent sequences:  A155168 A155169 A155170 * A155172 A155173 A155174

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jan 21 2009

STATUS

approved

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Last modified October 17 14:21 EDT 2019. Contains 328113 sequences. (Running on oeis4.)