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%I #9 Nov 07 2023 05:08:41
%S 3,4,6,18,150,60,30,22440,120360,44880,5610,11730,8160,473280,277440,
%T 131070,548760,920040,750720,440130,329970,27030,5689560,522240,1020,
%U 3028890,2639760,6866130,251430,134130,7481190,2390880,2664240,9926130,279480,9730290
%N Least k such that the least factor of k^Phi(k) -1 is the n-th prime.
%H Robert Price, <a href="/A066732/b066732.txt">Table of n, a(n) for n = 1..56</a>
%e 18^Phi(18)-1 = 18^6-1 = 34012223 = 7^3 * 17 * 19 * 307. Therefore since 7, the fourth prime, is the least prime in the factorization, a(4) = 18.
%t a = Table[0, {53} ]; Do[b = 1; While[ PowerMod[n, EulerPhi[n], Prime[b]] != 1, b++ ]; If[ a[[b]] == 0, a[[b]] = n], {n, 3, 10^6} ]
%Y Cf. A066699.
%K nonn
%O 1,1
%A _Robert G. Wilson v_, Jan 15 2002
%E a(35)-a(36) from _Robert Price_, Nov 06 2023