OFFSET
0,2
COMMENTS
Partial sums of golden rectangle numbers. The subsequence
EXAMPLE
a(19) = 0 + 2 + 6 + 15 + 24 + 40 + 60 + 77 + 104 + 135 +
PROG
(Python)
from math import isqrt
from itertools import count, islice
def A178129_gen(): # generator of terms
return accumulate(n*((isqrt(5*n**2<<2)>>1)+n+1>>1) for n in count(0))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, May 20 2010
STATUS
approved