OFFSET
0,2
COMMENTS
Matches first 8 odd primes.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..16384
FORMULA
a(n) = 1 + Sum_{i=1..n} A161841(i) for n > 0. - Christian Krause, Jun 17 2021
PROG
(PARI) a(n) = 1 + sqrtint(n) + sum(i=1, n, n\i); \\ Michel Marcus, Jun 17 2021
(Python)
from math import isqrt
def A132106(n): return (lambda m: 2*(sum(n//k for k in range(1, m+1)))+m*(1-m)+1)(isqrt(n)) # Chai Wah Wu, Oct 08 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Richard C. Schroeppel, Oct 31 2007
STATUS
approved