OFFSET
1,5
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
MAPLE
seq( add(add(`mod`(n, floor(k/j)), j=1..k), k=1..n), n=1..60); # G. C. Greubel, Dec 12 2019
MATHEMATICA
Table[Sum[Sum[Mod[n, Floor[k/j]], {j, k}], {k, n}], {n, 60}] (* G. C. Greubel, Dec 12 2019 *)
PROG
(PARI) a(n) = sum(k=1, n, sum(j=1, k, lift(Mod(n, k\j)) ));
vector(60, n, a(n)) \\ G. C. Greubel, Dec 12 2019
(Magma) [ &+[(&+[(n mod Floor(k/j)): j in [1..k]]): k in [1..n]]: n in [1..60]]; // G. C. Greubel, Dec 12 2019
(Sage) [sum(sum( n%floor(k/j) for j in (1..k)) for k in (1..n)) for n in (1..60)] # G. C. Greubel, Dec 12 2019
(GAP) List([1..60], n-> Sum([1..n], k-> Sum([1..k], j-> n mod Int(k/j)) )); # G. C. Greubel, Dec 12 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved