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.
%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