OFFSET
1,2
EXAMPLE
1(=1-0), 4(=4-0), 8(=9-1), 19(=20-1), 31(=35-4), 63(=66-3), 97(=105-8), etc.
PROG
(Python)
from math import isqrt
from sympy import npartitions
def A162362(n): return n*(npartitions(n)-n)-((s:=isqrt(n))**2*(s+1)-sum((q:=n//k)*((k<<1)+q+1) for k in range(1, s+1))>>1) # Chai Wah Wu, Oct 22 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jul 02 2009
EXTENSIONS
Entries checked by R. J. Mathar, May 21 2010
STATUS
approved