A218400 Numbers k such that the k-th triangular number contains only digits {0,4,7}.
284, 3080, 97680, 9460126854061817544
Offset: 1
Links
- G. Resta, Tridigital Triangular Numbers
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.
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