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A297492
a(n) = (1/2) * Sum_{|k|<=2*sqrt(p)} k^6*H(4*p-k^2) where H() is the Hurwitz class number and p is the n-th prime.
4
33, 308, 2874, 11528, 72060, 141218, 414918, 648260, 1394328, 3528690, 4608800, 9358298, 14113470, 17077148, 24378288, 39426858, 60555180, 69195410, 100714868, 127012680, 141942878, 194693840, 237229188, 313639470, 442561238, 520209690, 562658408, 655294428
OFFSET
1,1
LINKS
N. Lygeros, O. Rozier, A new solution to the equation tau(p) == 0 (mod p), J. Int. Seq. 13 (2010) # 10.7.4.
FORMULA
Let b(n) = 5*n^4 - 9*n^2 - 5*n - 1.
a(n) = b(prime(n)).
PROG
(PARI) b(n) = 5*n^4 - 9*n^2 - 5*n - 1;
a(n) = b(prime(n)); \\ Michel Marcus, Jan 01 2018
CROSSREFS
(1/2) * Sum_{|k|<=2*sqrt(p)} k^m*H(4*p-k^2): A000040 (m=0), A084920 (m=2), A297491 (m=4), this sequence (m=6), A297493 (m=8), A297494 (m=10).
Cf. A259825.
Sequence in context: A020291 A222726 A024400 * A256109 A241966 A210077
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 31 2017
STATUS
approved