OFFSET
0,2
LINKS
Juri-Stepan Gerasimov, x = A001511(A051027(A000079(x))), SeqFan list, Aug 19 2019.
EXAMPLE
PROG
(Magma) [Valuation(2*SumOfDivisors(SumOfDivisors(2^n)), 2): n in [0..89]];
(PARI) a(n) = valuation(2*sigma(sigma(2^n)), 2); \\ Michel Marcus, Aug 06 2019
(Python)
from sympy import divisor_sigma
def A309530(n): return ((m:=int(divisor_sigma((1<<n+1)-1)))&-m).bit_length() # Chai Wah Wu, Jul 13 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Aug 06 2019
STATUS
approved