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A280008
First differences of A002375.
2
0, 1, 0, 1, -1, 1, 0, 0, 0, 1, 0, 0, -1, 1, -1, 2, 0, -2, 1, 1, -1, 1, 1, -1, -1, 2, -2, 1, 2, -3, 2, 1, -4, 3, 1, -1, 0, 2, -3, 1, 3, -3, -1, 5, -5, 1, 2, -4, 3, 2, -3, 1, 2, -2, 1, 3, -4, 0, 6, -8, 1, 5, -7, 4, 2, -3, -1, 3, -1, 1, 3, -5, -1, 7, -8, 4, 3, -6, 3, 2, -5, 1, 7, -4, -3, 5, -4, 0, 7, -8, 2, 5, -8, 3, 3, -4, 2, 4, -5, 1, 5, -7, 0, 12, -13, 2, 5, -6, 2, 2, -4, 0, 5, -3, -2, 8, -6, 0, 9, -10
OFFSET
1,16
COMMENTS
See the perception of symmetry on scatterplot of this sequence that is also in Links section.
Are there infinitely many 0's in this sequence?
FORMULA
a(n) = A002375(n+1) - A002375(n).
PROG
(PARI) a002375(n) = sum(i=2, primepi(n), isprime(2*n - prime(i)));
a(n) = a002375(n+1) - a002375(n);
CROSSREFS
Sequence in context: A026610 A094451 A056562 * A135220 A347550 A068320
KEYWORD
sign
AUTHOR
Altug Alkan, Feb 21 2017
STATUS
approved