OFFSET
1,1
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 2*n + 4*ceiling(n*(1 + sqrt(5))/2). - Paolo Xausa, Mar 20 2024
MATHEMATICA
Array[2*# + 4*Ceiling[#*GoldenRatio] &, 100] (* Paolo Xausa, Mar 20 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 28 2005
STATUS
approved