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A362029
a(n) = Sum_{k=1..n} (-1)^(n-k) * k * mu(k)^2, where mu(k) is the Moebius function.
2
1, 1, 2, -2, 7, -1, 8, -8, 8, 2, 9, -9, 22, -8, 23, -23, 40, -40, 59, -59, 80, -58, 81, -81, 81, -55, 55, -55, 84, -54, 85, -85, 118, -84, 119, -119, 156, -118, 157, -157, 198, -156, 199, -199, 199, -153, 200, -200, 200, -200, 251, -251, 304, -304, 359, -359, 416, -358, 417, -417, 478, -416, 416
OFFSET
1,3
LINKS
FORMULA
G.f.: (Sum_{k>=1} mu(k)^2 * k * x^k) / (1 + x).
a(n) = -a(n-1) + |A055615(n)| for n > 1.
PROG
(PARI) a(n) = sum(k=1, n, (-1)^(n-k)*k*moebius(k)^2);
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Seiichi Manyama, Apr 05 2023
STATUS
approved