OFFSET
0,1
COMMENTS
Records occur in positions 0, 1, 2, 4, 7, 54, 139, 174, 225, 398, 778, and they are 2, 4, 5, 6, 8, 10, 11, 13, 16, 20, 21.
First 2's occur at positions 0, 3, 14, 15, 18, 21, 34, 65, 92, 135, 200, 255, 339, 362, 468, 511, 825, 1042, 1809.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..2049
EXAMPLE
See example in A260441. This sequence gives the number of those irreducible factors, counted with multiplicity. For example, a(0) = 2 (for 61 * 61), a(1) = 4 (for 3 * 3 * 3 * 299). Note that irreducibility here refers to irreducibility in ring GF(2)[X], as for example 299 = 13*23 when factored to ordinary primes.
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 04 2015
STATUS
approved