



4, 16, 24, 48, 63, 75, 115, 139, 199, 215, 250, 334, 382, 402, 438, 550, 580, 643, 787, 811, 891, 1071, 1092, 1140, 1239, 1267, 1339, 1559, 1679, 1943, 1975, 2020, 2090, 2233, 2293, 2605, 2773, 2809, 2929, 3293, 3338, 3434, 3629, 4049, 4161, 4161, 4385
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OFFSET

1,1


COMMENTS

Partial sums of, considering all Pythagorean triangles A^2 + B^2 = C^2 with A<B<C; sequence giveing values of B, sorted to correspond to increasing A (A009004(n)). The subsequence of primes in this partial sum begins: 139, 199, 643, 787, 811, 1559, 2293, 4049, 5051. The subsequence of squares in this partial sum begins: 4, 16, 2809.


LINKS

Table of n, a(n) for n=1..47.


FORMULA

a(n) = SUM[i=1..n] A156681(i).


EXAMPLE

a(8) = 4 + 12 + 8 + 24 + 15 + 12 + 40 + 24 = 139 is prime, where the 4 is from the (3,4,5) triangle, the 12 is from the (5,12,13), the 8 is from the (6,8,10), the 24 is from the (7,24,25) and so forth.


CROSSREFS

Cf. A156681, A156682, A009004, A009012, A009023.
Sequence in context: A284810 A192199 A145229 * A160996 A173926 A305884
Adjacent sequences: A174996 A174997 A174998 * A175000 A175001 A175002


KEYWORD

nonn


AUTHOR

Jonathan Vos Post, Apr 03 2010


STATUS

approved



