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 A050918 #38 Feb 16 2025 08:32:40 %S A050918 7,23,383,32212254719,2833419889721787128217599, %T A050918 195845982777569926302400511,4776913109852041418248056622882488319, %U A050918 1307960347852357218937346147315859062783,225251798594466661409915431774713195745814267044878909733007331390393510002687 %N A050918 Woodall primes: primes of form k*2^k-1. %H A050918 M. F. Hasler, <a href="/A050918/b050918.txt">Table of n, a(n) for n = 1..15</a> (all terms < 10^999). %H A050918 Ray Ballinger, <a href="http://web.archive.org/web/20161028080439/http://www.prothsearch.net/woodall.html">Woodall Primes: Definition and Status</a>. %H A050918 C. K. Caldwell, <a href="https://t5k.org/glossary/page.php?sort=WoodallNumber">Woodall Numbers</a>. %H A050918 Brady Haran and Matt Parker, <a href="https://www.youtube.com/watch?v=PQDvEJFdY1U">383 is cool</a>, Numberphile video, 2017. %H A050918 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/WoodallNumber.html">Woodall Number</a>. %F A050918 a(n) = A002234(n)*2^A002234(n) - 1. - _M. F. Hasler_, May 10 2017 %t A050918 Select[Table[n 2^n - 1, {n, 300}], PrimeQ] (* _Harvey P. Dale_, Jul 12 2012 *) %o A050918 (PARI) for(n=2,999,ispseudoprime(p=n*2^n-1)&&print1(p",")) \\ _M. F. Hasler_, May 10 2017 %o A050918 (Python) %o A050918 from sympy import isprime %o A050918 def auptok(limit): %o A050918 return list(filter(isprime, (k*2**k-1 for k in range(1, limit+1)))) %o A050918 print(auptok(1000)) # _Michael S. Branicky_, Jul 23 2021 %Y A050918 Cf. A002234, A003261. %K A050918 nonn,easy,nice %O A050918 1,1 %A A050918 _N. J. A. Sloane_, Dec 30 1999