Additive primes: sum of digits is a prime

Open in the 3-D viewerA046704 on the OEIS
| Terms | 100,000 (n = 1 … 100,000) |
|---|---|
| Decomposable (a > 2d) | 99,996 |
| Level class, k > L | 31,056 · 31.06 % |
| Weight class, k ≤ L | 68,940 · 68.94 % |
| Ties, k = L | 9 |
| On the level line L = 1 | 7,875 |
| Forced level, l ≤ d² | 29 |
| Range of a(n) | 2 … 3,723,581 |
| Range of the jump d | 1 … 362 |
| Largest weight k, level L | 3,723,047, 1,240,433 |
150 different gaps occur, from 1 to 362; the level share is 31.06 %.
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.