OFFSET
0,2
COMMENTS
First 127 terms computed by Davide M. Proserpio using ToposPro.
LINKS
Davide M. Proserpio, Table of n, a(n) for n = 0..127
V. A. Blatov, A. P. Shevchenko, D. M. Proserpio, Applied Topological Analysis of Crystal Structures with the Program Package ToposPro, Cryst. Growth Des. 2014, 14, 3576-3586.
Reticular Chemistry Structure Resource (RCSR), The bar tiling (or net)
FORMULA
Conjectured recurrence, found by gfun, using the command rec:=gfun[listtorec](t1, a(n)); (where t1 is a list of the initial terms) suggested by Paul Zimmermann. (Note: this should not be used to extend the sequence.)
a(n+1)=2*a(n+2)-2*a(n+3)+a(n+4)-a(n+7)+3*a(n+8)-4*a(n+9)+4*a(n+10)-2*a(n+11)+2*a(n+14) -4*a(n+15)+4*a(n+16)-3*a(n+17)+a(n+18)-a(n+21)+2*a(n+22)-2*a(n+23)+a(n+24),
with a(0) = 1, a(1) = 4, a(2) = 9, a(3) = 17, a(4) = 28, a(5) = 41, a(6) = 56, a(7) = 73, a(8) = 93, a(9) = 117, a(10) = 146, a(11) = 180, a(12) = 216, a(13) = 253, a(14) = 291, a(15) = 329, a(16) = 369, a(17) = 414, a(18) = 466, a(19) = 524, a(20) = 586, a(21) = 650, a(22) = 712, a(23) = 773.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 21 2018
STATUS
approved