A091464 a(n) is the smallest j such that 1/2 + 1/5 + 1/8 + ... + 1/j exceeds n.

17, 323, 6506, 130664, 2624438, 52713275, 1058774426, 21266052797, 427140088670

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Formula

The next term is approximately the previous term * e^3.

Mathematica

s = 0; k = 2; Do[ While[s = N[s + 1/k, 24]; s <= n, k += 3]; Print[k]; k += 3, {n, 1, 7}]

Crossrefs

Cf. A002387, A056053, A056054, A091462, A091463.

Sequence in context: A196455 A217960 A221583 * A015693 A029535 A099275

Adjacent sequences: A091461 A091462 A091463 * A091465 A091466 A091467

Keyword

nonn,more

Author

Robert G. Wilson v, Jan 12 2004

Extensions

a(8)-a(9) from Hugo Pfoertner, Dec 26 2019

Status

approved