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a(n) is the smallest prime q such that A305411(n) + q is a square.
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%I #19 Feb 03 2023 12:21:44

%S 13,11,19,107,101,257,467,173,167,1601,719,701,347,569,929,1931,479,

%T 467,719,1163,683,1613,2843,941,1997,1307,1907,2549,1823,6869,2957,

%U 1487,2141,2777,1931,1823,1811,4253,2273,4877,5711,2663,7673,5081,4871,4799,4643

%N a(n) is the smallest prime q such that A305411(n) + q is a square.

%C A305411 is conjectured to have only 103 terms.

%e A305411(2) = 5; 5 + 2 = 7, 5 + 3 = 8, 5 + 5 = 10, and 5 + 7 = 12 are not squares, but 5 + 11 = 16 = 4^2, so a(2) = 11.

%Y Cf. A000040, A000290, A305411.

%K nonn

%O 1,1

%A _Can Güllü_, Jan 16 2023