A305370 Index of 2^n in A109812.

1, 2, 3, 5, 8, 15, 29, 50, 103, 164, 417, 649, 1324, 2684, 5348, 10226, 21298, 41538, 84652, 165034, 322262, 646648, 1283556, 2584860, 5163368, 10271638, 20566708, 40308350, 80758553, 161522919, 322519008, 637135132

Offset

0,2

Comments

It would be nice to have a formula for a(n).

The data suggests that a(n) is growing very roughly like 2^n/3.261. - N. J. A. Sloane, Mar 29 2022

Links

Table of n, a(n) for n=0..31.

Rémy Sigrist, C++ program for A305370

Example

A109812(15) = 32 = 2^5, so a(5) = 15.

Prog

(C++) See Links section.

Crossrefs

Cf. A109812, A113233.

Sequence in context: A049861 A130476 A096592 * A192571 A215525 A192645

Adjacent sequences: A305367 A305368 A305369 * A305371 A305372 A305373

Keyword

nonn,more,base

Author

N. J. A. Sloane, Jun 02 2018

Extensions

a(14)-a(22) from Chai Wah Wu, Jun 04 2018

a(23)-a(24) from Giovanni Resta, Jun 06 2018

a(25)-a(26) from Rémy Sigrist, Dec 05 2021

a(27)-a(28) from Walter Trump, Apr 13 2022

a(29)-a(31) from Walter Trump, Apr 26 2022

Status

approved