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A051642 Values of A (the short leg) of a Pythagorean triangle with A and C (the hypotenuse) both prime and part of a twin prime. 6
3, 5, 11, 19, 29, 101, 349, 521, 569, 571, 661, 1091, 1489, 2269, 2341, 2549, 2659, 2729, 2731, 4049, 5279, 6359, 6871, 7559, 8231, 9721, 11719, 11779, 12071, 13339, 17291, 17921, 17959, 19429, 19889, 20231, 20359, 31541, 33179, 33751, 38651 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
All terms of the sequence must be part of a Pythagorean triple of the form (2u-1), 2u*(u-1), (2u^2 - 2u + 1). - Joshua Zucker, May 11 2006
LINKS
MATHEMATICA
Select[Table[{2n-1, 2n(n-1), 2n^2-2n+1}, {n, 20000}], AllTrue[{#[[1]], #[[3]]}, PrimeQ]&&AnyTrue[#[[1]]+{2, -2}, PrimeQ]&&AnyTrue[#[[3]]+{2, -2}, PrimeQ]&][[All, 1]] (* Harvey P. Dale, Oct 11 2021 *)
CROSSREFS
Sequence in context: A023233 A048161 A284034 * A007671 A259589 A090471
KEYWORD
nonn,easy
AUTHOR
Stuart M. Ellerstein (ellerstein(AT)aol.com)
EXTENSIONS
More terms from Joshua Zucker, May 11 2006
STATUS
approved

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Last modified March 29 08:13 EDT 2024. Contains 371265 sequences. (Running on oeis4.)