decompwlj 3D

Primes of the form 6x^2+55y^2

A139931 on the OEIS · family quadratic form

Weight–level plate of Primes of the form 6x^2+55y^2
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 viewerA139931 on the OEIS
Terms100,000 (n = 1 … 100,000)
Decomposable (a > 2d)99,998
Level class, k > L54,196 · 54.20 %
Weight class, k ≤ L45,802 · 45.80 %
Ties, k = L30
On the level line L = 124,220
Forced level, l ≤ d²358
Range of a(n)61 … 25,596,919
Range of the jump d18 … 2,328
Largest weight k, level L25,596,817, 1,343,737

146 different gaps occur, from 18 to 2,328; the level share is 54.20 %; L = 1 holds 45 % 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.