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A375482
a(n) is the number of points (k, prime(k)) at integer distance from the point (n, prime(n)) for k < n (where prime(k) denotes the k-th prime number).
1
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 2, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 2, 1, 1, 2, 2, 1, 0, 0, 2, 1, 1, 1, 2, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, 1, 1
OFFSET
1,38
EXAMPLE
The first terms, alongside the corresponding k's, are:
n a(n) k's
-- ---- ----
1 0 None
2 0 None
3 0 None
4 0 None
5 0 None
6 0 None
7 0 None
8 0 None
9 0 None
10 1 3
11 1 4
12 0 None
PROG
(PARI) { for (n = 1, #pp = primes(87), print1 (sum(k = 1, n-1, issquare((pp[n] - pp[k])^2 + (n - k)^2))", "); ); }
CROSSREFS
Cf. A163001.
Sequence in context: A117886 A145723 A085977 * A288424 A127325 A368750
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Aug 17 2024
STATUS
approved