OFFSET
1,1
COMMENTS
Included among the 313 terms less than 10^6 in this sequence are 70 semiprimes, among which are 9 twin prime products (323=17*19, 11663=107*109, 19043=137*139, 39203=197*199, 51983=227*229, 121103=347*349, 381923=617*619, 685583=827*829, 736163=857*859), 8 of the form p(2p+3) (5777=53*109, 10877=73*149, 75077=193*389, 100127=223*449, 161027=283*569, 430127=463*929, 635627=563*1129), and 4 of the form p(3p-2) (97921=181*541, 556421=431*1291, 636641=461*1381, 722261=491*1471).
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..10000
EXAMPLE
323 is in the sequence because Fibonacci(323) mod 323 = 1.
646 (=2*323) is in the sequence because Fibonacci(646) mod 646 = 645 and 645 == -1 (mod 646).
CROSSREFS
KEYWORD
nonn
AUTHOR
Jon E. Schoenfield, Dec 30 2016
STATUS
approved