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A191701
In base-2 lunar arithmetic, number of binary numbers x of length n such that x*x has no zeros.
1
1, 1, 1, 1, 2, 3, 5, 9, 15, 28, 50, 95, 174, 337, 637, 1231, 2373, 4618, 8974, 17567, 34387, 67561, 132945, 262096, 517373, 1023366, 2025627, 4014861, 7964971, 15814414, 31424805, 62490481, 124330234, 247514283, 492990898, 982307460, 1958093809, 3904594162, 7788271542, 15539347702, 31012331211
OFFSET
1,5
LINKS
D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]
D. Applegate, M. LeBrun, and N. J. A. Sloane, Dismal Arithmetic, J. Int. Seq. 14 (2011) # 11.9.8.
Van Vinh Dang, Nataliya Dodonova, Mikhail Dodonov, and Svetlana Korabelshchikova, Some Applications of Binary Lunar Arithmetic, Proceedings of the VI International Conference on Information Technology and Nanotechnology, Data Science Session (ITNT-DS 2020), Vol. 2667, 75-79.
Svetlana Korabelshchikova, Some applications of binary lunar arithmetic, talk in Russian with English slides, based on previous paper.
FORMULA
a(n) >= A167510(n). - Michael Chu, Oct 27 2023
EXAMPLE
a(7)=5 since the following five vectors all have lunar squares equal to 1111111111111: 1101011, 1101111, 1110111, 1111011, 1111111.
CROSSREFS
Sequence in context: A092424 A167510 A351359 * A066726 A124642 A370641
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Jun 12 2011, corrected Jun 13 2011
EXTENSIONS
a(20) through a(41) from N. J. A. Sloane, Jun 14 2011
STATUS
approved