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 A002643 M4340 N1817 #33 Jul 31 2024 09:50:22 %S A002643 7,11,26,45,83,125,140,182,197,201,216,239,258,311,330,353,444,467, %T A002643 482,486,524,539,558,600,752,771,843,881,885,923,980,999,1071,1113, %U A002643 1170,1223,1337,1356,1470,1664,1835,1869,1911,1949,1968,2021,2078,2120,2192 %N A002643 Numbers k such that (k^2 + k + 1)/19 is prime. %D A002643 A. J. C. Cunningham, Binomial Factorisations, Vols. 1-9, Hodgson, London, 1923-1929; see Vol. 1, pp. 245-259. %D A002643 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A002643 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A002643 Vincenzo Librandi, <a href="/A002643/b002643.txt">Table of n, a(n) for n = 1..1000</a> %H A002643 A. J. C. Cunningham, <a href="/A001912/a001912.pdf">Binomial Factorisations</a>, Vols. 1-9, Hodgson, London, 1923-1929. [Annotated scans of a few pages from Volumes 1 and 2] %t A002643 Select[Range[2500], PrimeQ[(#^2 + # + 1)/19] &] (* _Vincenzo Librandi_, Sep 25 2012 *) %o A002643 (PARI) is(n)=isprime((n^2+n+1)/19) \\ _Charles R Greathouse IV_, Jun 06 2017 %Y A002643 Cf. A002640, A002641, A002642, A002644. %K A002643 nonn,easy %O A002643 1,1 %A A002643 _N. J. A. Sloane_ %E A002643 More terms from _Jon E. Schoenfield_, May 06 2010