login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A280843
a(n) = A049502(sigma(n)).
1
0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 2, 3, 3, 6, 0, 3, 0, 0, 0, 6, 4, 0, 0, 4, 0, 0, 0, 3, 0, 7, 3, 0, 0, 7, 6, 0, 4, 8, 4, 4, 0, 0, 1, 6, 4, 2, 3, 0, 4, 0, 5, 7, 0, 10, 0, 0, 4, 0, 8, 5, 3, 0, 0, 5, 4, 2, 6, 2, 0, 4, 0, 10, 5, 8, 1, 0, 8, 0, 4, 3, 0, 9, 7, 6, 0, 10, 0, 5, 0, 0, 2, 12, 5, 6, 3, 5, 4, 7, 0, 8, 4, 5, 4
OFFSET
1,10
COMMENTS
a(n) = major index (2nd definition) of the sum of the divisors of n, i.e., sigma(n).
FORMULA
a(n) = A049502(A000203(n)).
EXAMPLE
For n = 10, sigma(10) = 18 and major index (2nd definition) of 18 is 2. So, a(10) = 2.
CROSSREFS
KEYWORD
nonn
AUTHOR
Indranil Ghosh, Jan 08 2017
STATUS
approved