login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A268496 Indices of records in A268630 (= a(n)^2+a(n+1) is prime). 3

%I #7 Feb 10 2016 15:47:37

%S 0,1,3,5,7,9,15,16,17,23,24,29,40,49,52,63,72,73,74,77,83,89,92,93,

%T 105,110,130,145,154,161,162,165,175,182,184,189,190,198,205,213,217,

%U 218,219,222,237,239,247,251,253,255,278,293,308,311,313,331,336,339,346,351,353,362,366

%N Indices of records in A268630 (= a(n)^2+a(n+1) is prime).

%C See A268497 for the actual record values.

%o (PARI) show(n, f="/tmp/b268496.txt", c=0, a=0, u=[a-1])={for(n=1, n, a>=u[#u]&&if(f, write(f, c++-1, " "n-1), print1(n-1", ")); u=setunion(u, [a]); while(#u>1&&u[2]==u[1]+1, u=u[^1]); for(k=u[1]+1, 9e9, !setsearch(u, k) && isprime(a*a+k) && (a=k) && break))}

%K nonn

%O 0,3

%A _M. F. Hasler_, Feb 09 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 13:13 EDT 2024. Contains 371947 sequences. (Running on oeis4.)