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 A155173 Short leg A of primitive Pythagorean triangles such that perimeter s is average 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
 3, 5, 15, 21, 41, 59, 89, 101, 131, 141, 153, 155, 203, 209, 215, 231, 309, 351, 395, 405, 453, 455, 495, 551, 743, 761, 825, 915, 981, 1001, 1149, 1193, 1295, 1343, 1365, 1421, 1529, 1659, 1853, 2105, 2171, 2205, 2255, 2373, 2409, 2411, 2451, 2513, 2561, 2649 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS With p=1, then q=2,a=3,b=4,c=5, and s=12-+1 (11, 13) both primes. LINKS 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, a]], {n, 8!}]; lst CROSSREFS Cf. A020882, A020886, A020884, A020883, A024364, A024406, A155171. Sequence in context: A101129 A177916 A128396 * A202505 A210111 A121219 Adjacent sequences:  A155170 A155171 A155172 * A155174 A155175 A155176 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Jan 21 2009 EXTENSIONS Name edited by Zak Seidov, Mar 21 2014 STATUS approved

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Last modified October 17 15:01 EDT 2019. Contains 328116 sequences. (Running on oeis4.)