The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A141137 Even Fibonacci pseudoprimes: even composite numbers k such that either (1) k divides Fibonacci(k-1) if k mod 5 = 1 or -1 or (2) k divides Fibonacci(k+1) if k mod 5 = 2 or -2. 8
 8539786, 12813274, 17340938, 33940178, 64132426, 89733106, 95173786, 187473826, 203211098, 234735586, 353686906, 799171066, 919831058, 1188287794, 1955272906, 2166139898, 2309861746, 2864860298, 3871638242, 5313594466, 5867301826 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These even Fibonacci pseudoprimes (FPPs) were found by Kenny Richardson (kenyai(AT)yahoo.com). See A081264 for odd FPPs and references. Be aware that some authors use the term "Fibonacci pseudoprime" for pseudoprimes in Lucas sequences. For example, see A005845 for Lucas V(1,-1) pseudoprimes. a(69) > 2.6 * 10^11. - Dana Jacobsen, May 25 2015 LINKS Dana Jacobsen, Table of n, a(n) for n = 1..68 Dorin Andrica and Ovidiu Bagdasar, Recurrent Sequences: Key Results, Applications, and Problems, Springer (2020), p. 88. Dorin Andrica and Ovidiu Bagdasar, On Generalized Lucas Pseudoprimality of Level k, Mathematics (2021) Vol. 9, 838. PROG (Perl) use ntheory ":all"; for (3..1e10) { my \$n = \$_<<1; \$e = (0, -1, 1, 1, -1)[\$n%5]; next unless \$e; say \$n unless (lucas_sequence(\$n, 1, -1, \$n+\$e))[0]; } # Dana Jacobsen, May 25 2015 CROSSREFS Cf. A081264. Sequence in context: A251173 A203824 A081639 * A184150 A236450 A237074 Adjacent sequences: A141134 A141135 A141136 * A141138 A141139 A141140 KEYWORD nice,nonn AUTHOR T. D. Noe, Jun 09 2008 EXTENSIONS a(19) from Giovanni Resta, Jul 20 2013 a(20)-a(21) from Dana Jacobsen, May 25 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 8 17:50 EST 2023. Contains 360149 sequences. (Running on oeis4.)