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 A088579 #25 Mar 26 2025 16:27:59
%S A088579 3,11,643,425987,1909526242005090307
%N A088579 Primes of the form n*x^n + (n-1)*x^(n-1) + . . . + x + 1 for x=2.
%C A088579 Sum of reciprocals = 0.4257999816852453227652727311..
%C A088579 Next term is too large to include.
%H A088579 Vaclav Kotesovec, <a href="/A088579/b088579.txt">Table of n, a(n) for n = 1..10</a> (terms 1..9 from Michel Marcus)
%e A088579 2*2^2 + 1*2 + 1 = 11 is prime.
%t A088579 Select[Table[1+Sum[k 2^k, {k,n}], {n,1000}], PrimeQ] (* _T. D. Noe_, Nov 15 2006 *)
%o A088579 (PARI) polypn2(n,p) = { my(x=n,y=1); for(m=1,p, y=y+m*x^m; ); return(y) }
%o A088579 trajpolyp(n1,k) = { my(s=0); for(x1=0,n1, y1 = polypn2(k,x1); if(isprime(y1),print1(y1, ","); s+=1.0/y1; ) ); }
%o A088579 trajpolyp(500,2)
%Y A088579 Cf. A055469 (for x=1), A088584 (for x=3), A088583 (for x=4).
%K A088579 nonn
%O A088579 1,1
%A A088579 _Cino Hilliard_, Nov 20 2003
%E A088579 Corrected by _T. D. Noe_ and _Don Reble_, Nov 15 2006