Balanced primes (of order one): primes which are the average of the previous prime and the following prime

Open in the 3-D viewerA006562 on the OEIS
| Terms | 100,000 (n = 1 … 100,000) |
|---|---|
| Decomposable (a > 2d) | 99,997 |
| Level class, k > L | 52,419 · 52.42 % |
| Weight class, k ≤ L | 47,578 · 47.58 % |
| Ties, k = L | 3 |
| On the level line L = 1 | 13,471 |
| Forced level, l ≤ d² | 1,001 |
| Range of a(n) | 5 … 56,206,697 |
| Range of the jump d | 6 … 6,970 |
| Largest weight k, level L | 56,206,649, 3,306,093 |
Primes that are the mean of their two neighbours. They are sparse (the 100,000th is 56,206,697), and the gaps are large and varied. The level share is 52.42 %; 1.0 % of terms are forced level (l <= d^2).
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.