A348391 Row sums of irregular triangle A348390.

3, 7, 18, 24, 48, 56, 87, 109, 147, 159, 235, 249, 301, 355, 434, 452, 563, 583, 705, 779, 859, 883, 1087, 1143, 1237, 1331, 1499, 1529, 1781, 1813, 2004, 2118, 2240, 2358, 2701, 2739, 2875, 3009, 3339, 3381, 3729, 3773

Offset

2,1

Links

Table of n, a(n) for n=2..43.

Formula

a(n) = Sum_{m=1..2*A002541(n)} A348390(n, m), for n >= 2.

a(n) = A153485(n) + A348392(n).

Example

a(5) = 2 + 3 + 4 + 5 + 1 + 4 + 1 + 1 + 2 + 1 = (1 + 1 + 1 + 2 + 1) + (2 + 3 + 4 + 5 + 4) = 6 + 18 = 24.

Mathematica

nterms=50; Table[Total[Flatten[Table[Join[Most[Divisors[k]], Range[2k, n, k]], {k, n}]]], {n, 2, nterms+1}] (* Paolo Xausa, Nov 23 2021 *)

Crossrefs

Cf. A002541, A348390.

Sequence in context: A384767 A102329 A331713 * A327321 A069143 A097007

Adjacent sequences: A348388 A348389 A348390 * A348392 A348393 A348394

Keyword

nonn,easy

Author

Wolfdieter Lang, Nov 07 2021

Status

approved