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.

A069615 a(1) = 3; a(2n) = smallest prime starting (in the most significant digits) with a(2n-1) (i.e., as a right concatenation of a(2n-1) and a number with no insignificant zeros); a(2n+1) = smallest prime ending in (the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

Table of values

n a(n)
1 3
2 31
3 131
4 1319
5 21319
6 213193
7 12213193
8 122131939
9 1122131939
10 112213193957
11 27112213193957
12 271122131939573
13 3271122131939573
14 327112213193957339
15 2327112213193957339
16 232711221319395733969
17 13232711221319395733969

List of values

[3, 31, 131, 1319, 21319, 213193, 12213193, 122131939, 1122131939, 112213193957, 27112213193957, 271122131939573, 3271122131939573, 327112213193957339, 2327112213193957339, 232711221319395733969, 13232711221319395733969]

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

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