0,6

A sequence B is called a reluctant sequence of sequence A, if B is triangle array read by rows: row number k coincides with first k elements of the sequence A. Sequence A140531 is the reluctant sequence of A131577. - Boris Putievskiy, Dec 12 2012

Table of n, a(n) for n=0..77.

Boris Putievskiy, Transformations Integer Sequences And Pairing Functions arXiv:1212.2732 [math.CO]

a(n) = floor(2^((n-2-t(t+1)/2)), where t=floor((-1+sqrt(8*n-7))/2), n>=1. - Boris Putievskiy, Dec 13 2012

Cf. A000079, A059268.

Sequence in context: A304784 A131644 A115346 * A117316 A109189 A264157

Adjacent sequences: A140528 A140529 A140530 * A140532 A140533 A140534

nonn

Paul Curtz, Jul 03 2008

approved