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Primes of the form n^2 + (n+1)^3.
3

%I #14 Dec 06 2015 23:07:51

%S 31,73,241,379,2341,3571,6121,9661,20359,47881,51949,60763,65521,

%T 119953,135151,291721,305119,378289,394201,427351,537841,689041,

%U 736921,761671,921889,1202041,1271161,1306693,1494313,1533871,1742161,1785961,1875751

%N Primes of the form n^2 + (n+1)^3.

%C For n^2 + (n+1)^3 to be a prime, n cannot be 1 modulo 3 whereas all a(n) are definitely 1 modulo 3. - Avik Roy (avik_3.1416(AT)yahoo.co.in), Feb 13 2009

%H Zak Seidov, <a href="/A155933/b155933.txt">Table of n, a(n) for n = 1..2000</a>

%F a(n) = m^2 + (m+1)^3 where m = A128958(n). - _Zak Seidov_, Dec 15 2013

%e 31 is in the sequence since 31 is prime and 31 = 2^2 + 3^3.

%t lst={};Do[p=(n+2)^2+(n+3)^3;If[PrimeQ[p],AppendTo[lst,p]],{n,0,2*5!}];lst...and/or...lst={};Do[p=n^2+(n+1)^3;If[PrimeQ[p],AppendTo[lst,p]],{n,0,2*5!}];lst

%Y Cf. A128958.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Jan 30 2009

%E Definition corrected by _Zak Seidov_, Jul 05 2013