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.

A349247 Least n-digit number k with only odd digits such that the k-th triangular number also has only odd digits.

Table of values

n a(n)
1 1
2 13
3 177
4 1777
5 15173
6 135173
7 3397973
8 13535137
9 135157537
10 1193111377
11 11979759377
12 119595919137
13 1195991117973
14 11979931335173
15 119777591993777
16 1199999593111377
17 11977793913551137
18 119593573333335733
19 1195935733333335733
20 11977593393931151137
21 119759371717733717537

List of values

[1, 13, 177, 1777, 15173, 135173, 3397973, 13535137, 135157537, 1193111377, 11979759377, 119595919137, 1195991117973, 11979931335173, 119777591993777, 1199999593111377, 11977793913551137, 119593573333335733, 1195935733333335733, 11977593393931151137, 119759371717733717537]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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