A049787 a(n) = T(n,n-2), array T as in A049783.

0, 0, 0, 0, 2, 2, 3, 4, 3, 4, 8, 4, 8, 8, 10, 5, 13, 9, 16, 10, 12, 13, 20, 11, 16, 16, 20, 17, 27, 13, 26, 20, 25, 24, 32, 12, 30, 26, 34, 24, 40, 19, 38, 30, 33, 34, 47, 26, 41, 33, 43, 33, 55, 38, 53, 33, 40, 41, 66, 30, 58, 48, 55, 42, 58

Offset

3,5

Links

G. C. Greubel, Table of n, a(n) for n = 3..1000

Formula

a(n) = Sum_{j=1..n-4} mod(n-2, floor((n-4)/j)). - G. C. Greubel, Dec 12 2019

Maple

seq( add(`mod`(n-2, floor((n-4)/j)), j=1..n-4), n=3..70); # G. C. Greubel, Dec 12 2019

Mathematica

Table[Sum[Mod[n-2, Floor[(n-4)/j]], {j, n-4}], {n, 3, 70}] (* G. C. Greubel, Dec 12 2019 *)

Prog

(PARI) vector(70, n, sum(j=1, n-2, lift(Mod(n, (n-2)\j))) ) \\ G. C. Greubel, Dec 12 2019
(Magma) [ n lt 5 select 0 else &+[((n-2) mod Floor((n-4)/j)): j in [1..n-4]]: n in [3..70]]; // G. C. Greubel, Dec 12 2019
(Sage) [sum( (n-2)%floor((n-4)/j) for j in (1..n-4)) for n in (3..70)] # G. C. Greubel, Dec 12 2019
(GAP) List([3..70], n-> Sum([1..n-4], j-> (n-2) mod Int((n-4)/j)) ); # G. C. Greubel, Dec 12 2019

Crossrefs

Cf. A049783, A049784, A049785, A049786, A049788, A049789.

Sequence in context: A235804 A051597 A084193 * A084192 A129595 A094508

Adjacent sequences: A049784 A049785 A049786 * A049788 A049789 A049790

Keyword

nonn

Author

Clark Kimberling

Status

approved