Concatenation of two or more consecutive positive integers

Open in the 3-D viewerA035333 on the OEIS
| Terms | 100,000 (n = 1 … 100,000) |
|---|---|
| Decomposable (a > 2d) | 99,995 |
| Level class, k > L | 99,853 · 99.86 % |
| Weight class, k ≤ L | 142 · 0.14 % |
| Ties, k = L | 0 |
| On the level line L = 1 | 5,459 |
| Forced level, l ≤ d² | 99,628 |
| Range of a(n) | 12 … 9,879,198,792 |
| Range of the jump d | 10 … 2,222,121 |
| Largest weight k, level L | 9,877,298,773, 3,106,144 |
106 different gaps occur, from 10 to 2,222,121; the level share is 99.86 %; 99.6 % of terms are forced level (l <= d^2); there are no ties.
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.