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A303052
Total area of all squares with squarefree side length |s - t|, such that n = s + t, and s < t, where s and t are positive integers.
0
0, 0, 1, 4, 10, 4, 35, 40, 84, 40, 84, 140, 205, 140, 374, 336, 599, 336, 888, 336, 1249, 336, 1690, 820, 2219, 820, 2219, 1496, 2219, 1496, 3060, 2396, 4021, 2396, 5110, 3552, 6335, 3552, 7704, 4996, 9225, 4996, 10906, 6760, 12755, 6760, 12755, 8876, 14964
OFFSET
1,4
FORMULA
a(n) = Sum_{i=1..floor((n-1)/2)} (n-2*i)^2 * mu(n-2*i)^2, where mu is the Möbius function (A008683).
MATHEMATICA
Table[Sum[(n - 2 i)^2 MoebiusMu[n - 2 i]^2, {i, Floor[(n - 1)/2]}], {n, 100}]
PROG
(PARI) a(n) = sum(i=1, (n-1)\2, (n-2*i)^2*moebius(n-2*i)^2); \\ Michel Marcus, Apr 17 2018
CROSSREFS
Cf. A008683.
Sequence in context: A128505 A336988 A200454 * A003564 A347116 A205016
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Apr 17 2018
STATUS
approved