A049788 a(n) = T(n,n-3), array T as in A049783.

0, 0, 0, 0, 1, 0, 4, 3, 4, 4, 8, 3, 9, 9, 11, 8, 12, 10, 17, 9, 13, 15, 23, 14, 17, 19, 22, 20, 30, 12, 27, 22, 26, 30, 35, 15, 29, 35, 35, 27, 43, 22, 39, 36, 34, 40, 56, 29, 42, 38, 45, 39, 58, 43, 54, 34, 45, 49, 69, 33, 59, 67, 56, 45, 63

Offset

4,7

Links

G. C. Greubel, Table of n, a(n) for n = 4..1000

Formula

a(n) = Sum_{j=1..n-6} mod(n-3, floor((n-6)/j)). - G. C. Greubel, Dec 12 2019

Maple

seq( add(`mod`(n-3, floor((n-6)/j)), j=1..n-6), n=4..70); # G. C. Greubel, Dec 12 2019

Mathematica

Table[Sum[Mod[n-3, Floor[(n-6)/j]], {j, n-6}], {n, 4, 70}] (* G. C. Greubel, Dec 12 2019 *)

Prog

(PARI) vector(70, n, sum(j=1, n-3, lift(Mod(n, (n-3)\j))) ) \\ G. C. Greubel, Dec 12 2019
(Magma) [n lt 7 select 0 else &+[((n-3) mod Floor((n-6)/j)): j in [1..n-6]]: n in [4..70]]; // G. C. Greubel, Dec 12 2019
(Sage) [sum( (n-3)%floor((n-6)/j) for j in (1..n-6)) for n in (4..70)] # G. C. Greubel, Dec 12 2019
(GAP) List([4..70], n-> Sum([1..n-6], j-> (n-3) mod Int((n-6)/j)) ); # G. C. Greubel, Dec 12 2019

Crossrefs

Cf. A049783, A049784, A049785, A049786, A049787, A049789.

Sequence in context: A239594 A094948 A332472 * A002558 A204671 A204816

Adjacent sequences: A049785 A049786 A049787 * A049789 A049790 A049791

Keyword

nonn

Author

Clark Kimberling

Status

approved