

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
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OFFSET

1,5


LINKS

Table of n, a(n) for n=1..41.
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, N. J. A. Sloane, Dismal Arithmetic, J. Int. Seq. 14 (2011) # 11.9.8.
Index entries for sequences related to dismal (or lunar) arithmetic


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: A060013 A092424 A167510 * A066726 A124642 A269153
Adjacent sequences: A191698 A191699 A191700 * A191702 A191703 A191704


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



