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 A083732 Pseudoprimes to bases 2 and 5. 2
 561, 1729, 2821, 5461, 6601, 8911, 12801, 13981, 15841, 29341, 41041, 46657, 52633, 63973, 68101, 75361, 101101, 113201, 115921, 126217, 137149, 162401, 172081, 188461, 252601, 294409, 314821, 334153, 340561, 399001, 401401, 410041, 488881 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. J. Mathar, Table of n, a(n) for n=1..169 F. Richman, Primality testing with Fermat's little theorem FORMULA a(n) = n-th positive integer k(>1) such that 2^(k-1) = 1 (mod k) and 5^(k-1) = 1 (mod k) Intersection of A001567 and A005936. - R. J. Mathar, Apr 05 2011 EXAMPLE a(1)=561 since 561 is the first positive integer k(>1) which satisfies 2^(k-1) = 1 (mod k) and 5^(k-1) = 1 (mod k) CROSSREFS Sequence in context: A048123 A131672 A224930 * A135720 A217465 A097130 Adjacent sequences:  A083729 A083730 A083731 * A083733 A083734 A083735 KEYWORD easy,nonn AUTHOR Serhat Sevki Dincer (sevki(AT)ug.bilkent.edu.tr), May 05 2003 STATUS approved

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