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A078462 Partial sums of A035185. 1
1, 2, 2, 3, 3, 3, 5, 6, 7, 7, 7, 7, 7, 9, 9, 10, 12, 13, 13, 13, 13, 13, 15, 15, 16, 16, 16, 18, 18, 18, 20, 21, 21, 23, 23, 24, 24, 24, 24, 24, 26, 26, 26, 26, 26, 28, 30, 30, 33, 34, 34, 34, 34, 34, 34, 36, 36, 36, 36, 36, 36, 38, 40, 41, 41, 41, 41, 43, 43, 43, 45, 46, 48, 48 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..74.

M. Baake and R. V. Moody, Similarity submodules and root systems in four dimensions, Canad. J. Math. 51 (1999), 1258-1276.

FORMULA

a(n) = Sum_{k=1..n} A035185(k);

a(n) is asymptotic to c*n where c = log(1+sqrt(2))/sqrt(2) = 0.62322524014023051339402008...

a(n) = Sum_{k=1..n} K(k,2)*floor(n/k) where K(x,y) is the Kronecker symbol. - Benoit Cloitre, Oct 31 2009

MATHEMATICA

Table[DivisorSum[n, KroneckerSymbol[2, #]&], {n, 1, 100}] // Accumulate (* Jean-Fran├žois Alcover, Nov 11 2018 *)

PROG

(PARI) a(n)=sum(k=1, n, kronecker(k, 2)*floor(n/k)) \\ Benoit Cloitre, Oct 31 2009

CROSSREFS

Cf. A035185, A078428.

Sequence in context: A240519 A318037 A326165 * A239518 A293924 A307730

Adjacent sequences:  A078459 A078460 A078461 * A078463 A078464 A078465

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Dec 31 2002

EXTENSIONS

Corrected by T. D. Noe, Nov 02 2006

STATUS

approved

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Last modified March 5 16:12 EST 2021. Contains 341825 sequences. (Running on oeis4.)