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 A216590 #11 Sep 10 2014 12:26:50 %S A216590 1669,1879,2089,2351,4969,5179,6047,10883,11923,12097,12143,12329, %T A216590 12539,12763,13049,13183,15413,15923,16187,16547,16741,17189,17581, %U A216590 18481,19993,20201,21433,21727,22303,22483,23021,23053,23831,24023,24749,25579,25633,26111,26561 %N A216590 Primes p with property that there exists a number d>0 such that numbers p-k*d, k=1...7, are seven primes. %C A216590 Conjecture: only 5254157 primes are not in the sequence: 2, 3, ..., 5082095279. %C A216590 Conjecture: for any k>0 there exists p0 such that for any prime p>p0 there exists a k-term arithmetic progression of primes with p at the end. %e A216590 1669 is in the sequence because with d=210: 1459, 1249, 1039, 829, 619, 409, 199 are all primes. %o A216590 (PARI) is(n)=my(t); forprime(p=2,n-26,if((n-p)%7==0 && isprime((t=(n-p)/7)+p) && isprime(2*t+p) && isprime(3*t+p) && isprime(4*t+p) && isprime(5*t+p) && isprime(6*t+p) && isprime(n), return(1))); 0 \\ _Charles R Greathouse IV_, Sep 10 2014 %Y A216590 Cf. A216495, A094383, A216497, A216498, A216468. %K A216590 nonn %O A216590 1,1 %A A216590 _Alex Ratushnyak_, Sep 09 2012