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A305117
a(n) = A304651(n)/4.
3
0, 1, 2, 2, 2, 4, 4, 4, 4, 4, 6, 6, 6, 8, 8, 8, 8, 10, 10, 10, 10, 10, 10, 10, 10, 12, 14, 14, 14, 16, 16, 16, 16, 16, 18, 18, 18, 20, 20, 20, 20, 22, 22, 22, 22, 22, 22, 22, 22, 22, 24, 24, 24, 26, 26, 26, 26, 26, 28, 28, 28, 30, 30, 30, 30, 34, 34, 34, 34, 34, 34
OFFSET
0,3
LINKS
FORMULA
a(n) = a(n-1) + A000089(n) for n > 0.
MATHEMATICA
a89[n_] := a89[n] = Product[{p, e} = pe; Which[p < 3 && e == 1, 1, p == 2 && e > 1, 0, Mod[p, 4] == 1, 2, Mod[p, 4] == 3, 0, True, a89[p^e]], {pe, FactorInteger[n]}];
a[n_] := a[n] = If[n == 0, 0, a[n-1] + a89[n]];
Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Aug 02 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 26 2018
STATUS
approved