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 A208400 Smallest integer k such that k*n+1 is a prime dividing (n^n)^2 + 1. 1
 8, 24, 16384, 8, 216, 1937780208, 24, 720, 167632, 22896, 8, 29256, 72, 2240, 3728099320468576, 8, 612214200, 64, 3800, 176, 40, 18624, 8, 160, 336, 19656, 280, 270006232334172274751152473116790619162839546306934626321438592627063115205009840, 8, 13392, 8568 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 LINKS EXAMPLE a(3) = 24 because (3^3)^2 + 1 =2*5*73 and the smallest prime divisor of the form k*n+1 is 73 = 24*3+1 => k = 24. MATHEMATICA Table[p=First/@FactorInteger[(n^n)^2+1]; (Select[p, Mod[#1, n] == 1 &, 1][[1]] - 1)/n, {n, 2, 20}] CROSSREFS Cf. A208399. Sequence in context: A166483 A274303 A132586 * A103953 A076444 A023056 Adjacent sequences:  A208397 A208398 A208399 * A208401 A208402 A208403 KEYWORD nonn AUTHOR Michel Lagneau, Feb 27 2012 STATUS approved

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Last modified June 26 10:23 EDT 2022. Contains 354879 sequences. (Running on oeis4.)