OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 5*n + A022839(2*n). - R. J. Mathar, Aug 25 2011
a(n) = floor(n*(5+2*sqrt(5))). - Vincenzo Librandi, Oct 25 2011
MATHEMATICA
PROG
(Magma) [Floor(n*(5+2*Sqrt(5))): n in [1..80]]; // Vincenzo Librandi, Oct 25 2011
(Python)
from sympy import integer_nthroot
def A194152(n): return 5*n+integer_nthroot(20*n**2, 2)[0] # Chai Wah Wu, Mar 16 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Aug 17 2011
STATUS
approved