Numbers with the property that every pair of adjacent digits sum to a prime number

Open in the 3-D viewerA182175 on the OEIS
| Terms | 100,000 (n = 1 … 100,000) |
|---|---|
| Decomposable (a > 2d) | 99,997 |
| Level class, k > L | 14,514 · 14.51 % |
| Weight class, k ≤ L | 85,483 · 85.49 % |
| Ties, k = L | 7 |
| On the level line L = 1 | 6,646 |
| Forced level, l ≤ d² | 733 |
| Range of a(n) | 0 … 58,385,076 |
| Range of the jump d | 1 … 3,434,344 |
| Largest weight k, level L | 58,383,019, 29,192,514 |
87 different gaps occur, from 1 to 3,434,344; the level share is 14.51 %; L = 1 holds 46 % 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.