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A305429 Largest k < n whose binary expansion encodes an irreducible (0,1)-polynomial over Q, with a(1) = a(2) = 1. 4
1, 1, 2, 3, 3, 5, 5, 7, 7, 7, 7, 11, 11, 13, 13, 13, 13, 17, 17, 19, 19, 19, 19, 23, 23, 25, 25, 25, 25, 29, 29, 31, 31, 31, 31, 31, 31, 37, 37, 37, 37, 41, 41, 43, 43, 43, 43, 47, 47, 47, 47, 47, 47, 53, 53, 55, 55, 55, 55, 59, 59, 61, 61, 61, 61, 61, 61, 67, 67, 69, 69, 71, 71, 73, 73, 73, 73, 77, 77, 79, 79, 81, 81, 83, 83, 83, 83, 87, 87 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
For n >= 3, a(n) is the largest term of A206074 less than n.
LINKS
PROG
(PARI)
A257000(n) = polisirreducible(Pol(binary(n)));
A305429(n) = if(n<3, 1, my(k=n-1); while(k>1 && !A257000(k), k--); (k));
CROSSREFS
Cf. also A151799 (A136548), A305419.
Sequence in context: A136548 A007917 A151799 * A093841 A281354 A283313
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 07 2018
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)