decompwlj 3D

a(n) = floor(n*phi^5), where phi is the golden ratio, A001622

A004920 on the OEIS · family Beatty

Weight–level plate of a(n) = floor(n*phi^5), where phi is the golden ratio, A001622
Click the plate to explore it in 3-D. Weight k across, level L up, both on log scales: blue in the weight class (k ≤ L), orange in the level class (k > L). The dashed diagonal is k = L.
Open in the 3-D viewerA004920 on the OEIS
Terms100,000 (n = 0 … 99,999)
Decomposable (a > 2d)99,997
Level class, k > L25,807 · 25.81 %
Weight class, k ≤ L74,190 · 74.19 %
Ties, k = L13
On the level line L = 17,773
Forced level, l ≤ d²9
Range of a(n)0 … 1,109,005
Range of the jump d11 … 12
Largest weight k, level L1,108,817, 92,407

The gaps are 11 and 12; the level share is 25.81 %; L = 1 holds 30 % of the level class.

The decomposition

Every term of a strictly increasing sequence is written a(n) = k(n)·L(n) + d(n): the jump d = a(n+1) − a(n), the weight k the least divisor of a − d greater than d, the level L = (a − d)/k. A term decomposes when a > 2d; it is in the level class when k > L and in the weight class when k ≤ L. See decompwlj.com and arXiv:0711.0865, or how it works, with worked examples and a live one.