login
A358435
Row sums of the triangular array A357498.
1
1, 4, 8, 16, 22, 36, 47, 68, 81, 105, 125, 155, 169, 220, 239, 300, 326, 365, 414, 475, 500, 572, 635, 705, 734, 830, 897, 966, 1009, 1151, 1195, 1318, 1373, 1490, 1566, 1672, 1734, 1903, 1971, 2107, 2221, 2390, 2461, 2580, 2689, 2887, 2963, 3176, 3276, 3450, 3580, 3789, 3868
OFFSET
1,2
COMMENTS
The rows of the triangular array A357498 are chains of numbers that end with the positive terms of A007952.
EXAMPLE
For row n=6, the next greater multiples are 6, 10, 12, 15, 16, and 17. These, divided by n..1 result in 1, 2, 3, 5, 8, and 17, the sum of which is a(6) = 36.
MATHEMATICA
a[n_] := Module[{k = n, s = Table[0, n], r}, s[[1]] = 1; Do[k++; k += If[(r = Mod[k, i]) == 0, 0, i - Mod[k, i]]; s[[n + 1 - i]] = k/i, {i, n - 1, 1, -1}]; Total[s]]; Array[a, 50] (* Amiram Eldar, Nov 16 2022 *)
PROG
(PARI) a(n) = my(v=vector(n)); v[1] = n; for (k=2, n, v[k] = v[k-1] + (n-k+1) - (v[k-1] % (n-k+1)); ); vecsum(vector(n, k, v[k]/(n-k+1))); \\ Michel Marcus, Nov 16 2022
CROSSREFS
Sequence in context: A053688 A036302 A032377 * A312823 A133690 A097057
KEYWORD
nonn
AUTHOR
Tamas Sandor Nagy, Nov 16 2022
EXTENSIONS
More terms from Thomas Scheuerle, Nov 16 2022
STATUS
approved