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 A057652 #13 Jun 13 2017 02:19:37
%S A057652 1,2,3,5,11,17,647
%N A057652 Numbers n such that n-2^k is a lucky number for all k such that 1 < 2^k < n.
%C A057652 Perhaps there are no more terms?
%C A057652 Lucky numbers have asymptotic properties very similar to prime numbers, so one can conjecture finiteness of this sequence in the same way as Erdős did for A039669, and this should generalize to any sequence created using a similar sieve. - _M. F. Hasler_, Oct 15 2010
%e A057652 647 is in this sequence since 647-2, 647-4, 647-8, 647-16, 647-32, 647-64, 647-128, 647-256, 647-512 are all members of the sequence A000959 of lucky numbers. - _M. F. Hasler_, Oct 15 2010
%o A057652 (PARI) A057652(Nmax) = { my(v=vector(Nmax\2,i,2*i-1)); for(i=2,#v,v[i]>#v && break; v=vecextract(v,2^#v-1-sum(k=1,#v\v[i],2^(v[i]*k))>>1)); v=Set(v); for(n=1,Nmax, for(k=1,Nmax, 2^k<n || break; setsearch(v,n-2^k) || next(2)); print1(n",")) } /* _M. F. Hasler_, Oct 15 2010 */
%Y A057652 Cf. A000959, A039669.
%K A057652 nonn,hard,more
%O A057652 1,2
%A A057652 _Naohiro Nomoto_, Oct 14 2000
%E A057652 Added initial terms {1, 2}, reworded definition following a suggestion from D. Forgues. - _M. F. Hasler_, Oct 15 2010