cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A091680 Smallest number whose base-4 Reverse and Add! trajectory (presumably) contains exactly n base-4 palindromes, or -1 if there is no such number.

Table of values

n a(n)
0 290
1 78
2 18
3 6
4 3
5 36
6 21
7 19
8 7
9 8
10 4
11 2
12 1
13 -1
14 -1
15 -1
16 -1
17 -1
18 -1
19 -1
20 -1

List of values

[290, 78, 18, 6, 3, 36, 21, 19, 7, 8, 4, 2, 1, -1, -1, -1, -1, -1, -1, -1, -1]