decompwlj 3D

Divisible only by primes congruent to 1 mod 3

A004611 on the OEIS · family multiplicative

Weight–level plate of Divisible only by primes congruent to 1 mod 3
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 viewerA004611 on the OEIS
Terms100,000 (n = 1 … 100,000)
Decomposable (a > 2d)99,997
Level class, k > L32,574 · 32.57 %
Weight class, k ≤ L67,423 · 67.43 %
Ties, k = L107
On the level line L = 119,966
Forced level, l ≤ d²9
Range of a(n)1 … 1,250,833
Range of the jump d6 … 84
Largest weight k, level L1,250,761, 178,681

14 different gaps occur, from 6 to 84; the level share is 32.57 %; L = 1 holds 61 % 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.