decompwlj 3D

Sequence S such that 1 is in S and if x is in S, then 3x-1 and 3x+1 are in S

A147991 on the OEIS · family self-referential

Weight–level plate of Sequence S such that 1 is in S and if x is in S, then 3x-1 and 3x+1 are in S
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 viewerA147991 on the OEIS
Terms100,000 (n = 1 … 100,000)
Decomposable (a > 2d)99,997
Level class, k > L9,321 · 9.32 %
Weight class, k ≤ L90,676 · 90.68 %
Ties, k = L1
On the level line L = 116
Forced level, l ≤ d²564
Range of a(n)1 … 50,383,499
Range of the jump d1 … 14,348,908
Largest weight k, level L21,523,359, 16,794,499

17 different gaps occur, from 1 to 14,348,908; the level share is 9.32 %; L = 3 holds 62 % 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.