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A278637
Numbers k such that Fibonacci(k) is either prime or semiprime.
1
3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 17, 19, 22, 23, 26, 29, 31, 34, 41, 43, 47, 53, 59, 61, 71, 73, 79, 83, 89, 94, 101, 107, 109, 113, 121, 127, 131, 137, 151, 167, 173, 191, 193, 199, 227, 251, 271, 277, 293, 331, 353, 359, 397, 401, 431, 433, 449, 467, 509, 569, 571, 587, 599, 601, 613, 631, 653, 743, 991, 1091, 1223, 1373, 1487
OFFSET
1,1
COMMENTS
Numbers k such that 2 <= A063375(k) <= 4.
All numbers in the first 4 rows of A279021 are in this sequence (3, 5, 11, 17, 353, 431, 509, and 587).
Are all numbers of A279021 in this sequence?
FORMULA
CROSSREFS
KEYWORD
nonn
AUTHOR
Bobby Jacobs, Jan 04 2017
EXTENSIONS
a(31)-a(64) from Charles R Greathouse IV, Jan 04 2017
a(65)-a(73) from Max Alekseyev, Feb 26 2023
STATUS
approved