A049789 a(n) = T(n,n-4), array T as in A049783.

0, 0, 0, 0, 0, 0, 1, 0, 5, 5, 7, 4, 7, 10, 6, 9, 14, 10, 17, 10, 14, 16, 24, 12, 19, 20, 24, 18, 32, 16, 25, 23, 30, 31, 33, 19, 31, 34, 43, 28, 45, 26, 41, 37, 37, 41, 61, 27, 44, 39, 49, 41, 63, 47, 58, 35, 48, 54, 76, 37, 61, 68, 65, 46, 65

Offset

5,9

Links

G. C. Greubel, Table of n, a(n) for n = 5..1000

Formula

a(n) = Sum_{j=1..n-8} mod(n-4, floor((n-8)/j)). - G. C. Greubel, Dec 12 2019

Maple

seq( add(`mod`(n-4, floor((n-8)/j)), j=1..n-8), n=5..70); # G. C. Greubel, Dec 12 2019

Mathematica

Table[Sum[Mod[n-4, Floor[(n-8)/j]], {j, n-8}], {n, 5, 70}] (* G. C. Greubel, Dec 12 2019 *)

Prog

(PARI) vector(70, n, sum(j=1, n-4, lift(Mod(n, (n-4)\j))) ) \\ G. C. Greubel, Dec 12 2019
(Magma) [ n lt 9 select 0 else &+[((n-4) mod Floor((n-8)/j)): j in [1..n-8]]: n in [5..70]]; // G. C. Greubel, Dec 12 2019
(Sage) [sum( (n-4)%floor((n-8)/j) for j in (1..n-8)) for n in (5..70)] # G. C. Greubel, Dec 12 2019
(GAP) List([5..70], n-> Sum([1..n-8], j-> (n-4) mod Int((n-8)/j)) ); # G. C. Greubel, Dec 12 2019

Crossrefs

Cf. A049783, A049784, A049785, A049786, A049787, A049788.

Sequence in context: A113272 A222392 A049471 * A234473 A011500 A003103

Adjacent sequences: A049786 A049787 A049788 * A049790 A049791 A049792

Keyword

nonn

Author

Clark Kimberling

Status

approved