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 A267824 #37 Dec 20 2018 02:01:48 %S A267824 283686649,4514260853041 %N A267824 Composite numbers n such that binomial(2n-1, n-1) == 1 (mod n^2). %C A267824 Babbage proved the congruence holds if n > 2 is prime. %C A267824 See A088164 and A263882 for references, links, and additional comments. %C A267824 Conjecture: n is a term if and only if n = A088164(i)^2 for some i >= 1 (cf. McIntosh, 1995, p. 385). - _Felix Fröhlich_, Jan 27 2016 %C A267824 The "if" part of the conjecture is true: see the McIntosh reference. - _Jonathan Sondow_, Jan 28 2016 %C A267824 The above conjecture implies that this sequence and A228562 are disjoint. - _Felix Fröhlich_, Jan 27 2016 %C A267824 Composites c such that A281302(c) > 1. - _Felix Fröhlich_, Feb 21 2018 %H A267824 Richard J. McIntosh, <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa71/aa7144.pdf">On the converse of Wolstenholme's Theorem</a>, Acta Arithmetica, 71 (1995), 381-389. %H A267824 J. Sondow, Extending Babbage's (non-)primality tests, in <a href="https://doi.org/10.1007/978-3-319-68032-3_19">Combinatorial and Additive Number Theory II</a>, Springer Proc. in Math. & Stat., Vol. 220, 269-277, CANT 2015 and 2016, New York, 2017; <a href="http://arxiv.org/abs/1812.07650">arXiv:1812.07650 [math.NT]</a>, 2018. %e A267824 a(1) = 16843^2 and a(2) = 2124679^2 are squares of Wolstenholme primes A088164. %Y A267824 Cf. A000984, A034602, A082180, A088164, A099905, A099906, A099907, A099908, A136327, A177783, A212557, A228562, A242473, A244214, A244919, A246130, A246132, A246133, A246134, A260209, A260210, A263429, A263882, A281302. %K A267824 nonn,bref,hard,more %O A267824 1,1 %A A267824 _Jonathan Sondow_, Jan 25 2016