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A049791 a(n) = Sum_{k=1..n} T(n,k), array T as in A049790. 7
1, 5, 14, 30, 54, 91, 137, 202, 280, 380, 492, 644, 799, 994, 1212, 1471, 1735, 2071, 2400, 2811, 3232, 3709, 4190, 4804, 5380, 6046, 6739, 7535, 8297, 9246, 10115, 11153, 12184, 13320, 14458, 15839, 17074, 18493, 19931, 21583, 23100, 24942, 26609, 28564, 30517, 32593, 34585, 37048, 39231, 41735, 44187, 46911 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

MAPLE

seq( add(add(floor(n/floor(k/j)), j=1..k), k=1..n), n=1..60); # G. C. Greubel, Dec 10 2019

MATHEMATICA

Table[Sum[Sum[Floor[n/Floor[k/j]], {j, k}], {k, n}], {n, 1, 60}] (* G. C. Greubel, Dec 10 2019 *)

PROG

(PARI) a(n) = sum(k=1, n, sum(j=1, k, n\(k\j) ));

vector(60, n, a(n)) \\ G. C. Greubel, Dec 10 2019

(MAGMA) [ &+[(&+[Floor(n/Floor(k/j)): j in [1..k]]): k in [1..n]] n in [1..60]]; // G. C. Greubel, Dec 10 2019

(Sage) [sum(sum(floor(n/floor(k/j)) for j in (1..k)) for k in (1..n)) for n in (1..60)] # G. C. Greubel, Dec 10 2019

(GAP) List([1..60], n-> Sum([1..n], k-> Sum([1..k], j-> Int(n/Int(k/j)) ))); # G. C. Greubel, Dec 10 2019

CROSSREFS

Cf. A049790, A049792, A049793, A049794, A049795, A049796.

Sequence in context: A256986 A162208 A161698 * A053461 A136135 A231673

Adjacent sequences:  A049788 A049789 A049790 * A049792 A049793 A049794

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Terms a(40) onward added by G. C. Greubel, Dec 10 2019

STATUS

approved

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Last modified May 17 00:16 EDT 2021. Contains 343957 sequences. (Running on oeis4.)