A345984 Partial sums of A011772.

1, 4, 6, 13, 17, 20, 26, 41, 49, 53, 63, 71, 83, 90, 95, 126, 142, 150, 168, 183, 189, 200, 222, 237, 261, 273, 299, 306, 334, 349, 379, 442, 453, 469, 483, 491, 527, 546, 558, 573, 613, 633, 675, 707, 716, 739, 785, 817, 865, 889, 906, 945, 997, 1024, 1034, 1082, 1100, 1128, 1186, 1201, 1261

Offset: 1

Author

N. J. A. Sloane, Jul 09 2021

Keywords

• nonn

Comments

How fast is this growing?

Links

• N. J. A. Sloane, Table of n, a(n) for n = 1..16383

Crossrefs

Cf. A011772, A344005, A345983.

Programs

Mathematica

Accumulate[(Sqrt[1+8#]-1)/2&/@Flatten[With[{r=Accumulate[ Range[ 300]]},Table[ Select[ r,Divisible[#,n]&,1],{n,80}]]]] (* Harvey P. Dale, Sep 19 2021 *)