cp's OEIS Frontend

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.

A129830 Conjectured first occurrence of numbers n with the property that there exist two consecutive primes p and q such that pq + n is a fourth power.

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%I A129830 #2 Oct 01 2013 21:35:22
%S A129830 1,4,9,10,25,35,36,46,49,64,66,75,113,144,149,179,188,196,203,221,241,
%T A129830 250,290,302,380,395,397,400
%N A129830 Conjectured first occurrence of numbers n with the property that there exist two consecutive primes p and q such that pq + n is a fourth power.
%C A129830 It remains to prove that for certain n, pq+n != y^4 for all consecutive primes p and q. This list was computed for p and q with prime indices up to 10000.
%e A129830 p=7,q=11,k=4. 7*11+4 = 81 = 3^4.
%o A129830 (PARI) primefourth(n,m) = { local(c,k,x,p1,p2,j); c=0; for(k=1,m, for(x=1,n, p1=prime(x); p2=(prime(x+1)); y=p1*p2+k; if(isfourth(y), c++; print1(k","); break; ) ) ); c; } isfourth(n) = \Return 1 if n is a fourth power { local(r); r = sqrt(sqrt(n)); if(floor(r+.5)^4== n,1,0) }
%Y A129830 Cf. A129783.
%K A129830 easy,nonn
%O A129830 1,2
%A A129830 _Cino Hilliard_, May 21 2007