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.

A215647 Smallest semiprime whose decimal expansion consists of the concatenation of a 1-digit semiprime, a 2-digit semiprime, a 3-digit semiprime, ..., and an n-digit semiprime.

Table of values

n a(n)
1 4
2 415
3 410111
4 4101061003
5 410106100310003
6 410106100310001100001
7 4101061003100011000011000057
8 410106100310001100001100000110000051
9 410106100310001100001100000110000001100000001

List of values

[4, 415, 410111, 4101061003, 410106100310003, 410106100310001100001, 4101061003100011000011000057, 410106100310001100001100000110000051, 410106100310001100001100000110000001100000001]

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

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