A147613 - OEIS

A147613

Numbers that are not Jacobsthal numbers.

2, 4, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

The nonnegative integers not occurring in A001045.

A147612(a(n)) = 0.

The formula below is a consequence of the Lambek-Moser theorem.

LINKS

Table of n, a(n) for n=1..71.

Wikipedia, Lambek-Moser theorem

FORMULA

a(n) = floor(-LambertW(-1, -(1/3)*log(2)*2^(3/2-n))/log(2) + 1/2). - Nicolas Normand (Nicolas.Normand(at)polytech.univ-nantes.fr), Nov 29 2017