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 A075766 #42 Jun 12 2025 12:58:02 %S A075766 2,7,8,10,17,20,25,28,31,38,61,62,355,4690,4772,8162,10523,14716, %T A075766 32114,117712 %N A075766 Numbers k such that A007923(k) is prime. %C A075766 SDS(355) certified prime with Primo. %C A075766 No more terms <= 8000. - _XU Pingya_, May 30 2017 %H A075766 Jason Earls, <a href="http://www.gallup.unm.edu/~smarandache/SNBook14.pdf">Some Results Concerning the Smarandache Deconstructive Sequence</a>, Smarandache Notions Journal, Volume 14 Issue 1, January 2004, Pages 222-226. %H A075766 Shyam Sunder Gupta, <a href="https://fs.unm.edu/ScientiaMagna2no3.pdf">Primes in the Smarandache deconstructive sequence</a>, Scientia Magna Vol. 2 (2006), No. 3, 26-30. Reports the three probable primes for k= 4690, 4772, and 8162. %H A075766 Shyam Sunder Gupta, <a href="https://listserv.nodak.edu/cgi-bin/wa.exe?A2=NMBRTHRY;dfd8f2fe.2404&S=">Memorable Prime</a>, Number Theory Mailing List, Mar 07 2024. Reports the 32114-digit prime. %o A075766 (PARI) isok(n) = my(m=(n*(n+1)/2-1)%9+1); isprime(sum(k=0, n-1, 10^k*((m-k-1)%9+1))); \\ _Michel Marcus_, May 30 2017 %Y A075766 Cf. A007923. %K A075766 more,nonn %O A075766 1,1 %A A075766 _Jason Earls_, Oct 09 2002 %E A075766 a(14)-a(15) from _XU Pingya_, May 30 2017 %E A075766 a(16)-a(18) from _Michael S. Branicky_, Jun 22 2023 %E A075766 a(19) from _Michael S. Branicky_, Nov 18 2024 %E A075766 a(20) from _Michael S. Branicky_, Jun 12 2025