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.

A114101 Begin with prime(1), then prime(2). After prime(j) write all the primes of the form prime(i) concatenated with prime(j) with i then prime(j+1).

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%I A114101 #9 Jun 24 2023 01:25:44
%S A114101 2,3,23,5,7,37,11,211,311,13,313,17,317,1117,19,719,1319,23,223,523,
%T A114101 1123,1723,29,229,1129,31,331,1931,37,337,3137,41,241,541,1741,2341,
%U A114101 43,743,47,347,547,1747,2347,53,353,1153,1753,2953,4153,59,359
%N A114101 Begin with prime(1), then prime(2). After prime(j) write all the primes of the form prime(i) concatenated with prime(j) with i<j; then prime(j+1).
%H A114101 Michael S. Branicky, <a href="/A114101/b114101.txt">Table of n, a(n) for n = 1..10000</a>
%e A114101 11 is followed by 211, 311 (511 and 711 are not primes); then 13.
%o A114101 (Python)
%o A114101 from itertools import islice
%o A114101 from sympy import isprime, nextprime
%o A114101 def agen(): # generator of terms
%o A114101     p, s = 2, []
%o A114101     while True:
%o A114101         yield p; sp = str(p); s.append(sp); p = nextprime(p)
%o A114101         yield from filter(isprime,  (int("".join(si + sp)) for si in s))
%o A114101 print(list(islice(agen(), 51))) # _Michael S. Branicky_, Jun 23 2023
%Y A114101 Cf. A114007.
%K A114101 base,nonn
%O A114101 1,1
%A A114101 _Amarnath Murthy_, Nov 20 2005
%E A114101 More terms from Amy Postell (arp179(AT)psu.edu), Feb 02 2006
%E A114101 Offset changed to 1 by _Michael S. Branicky_, Jun 23 2023