|
|
A296512
|
|
a(n) is the largest subpart of the symmetric representation of sigma(n).
|
|
3
|
|
|
1, 3, 2, 7, 3, 11, 4, 15, 5, 9, 6, 23, 7, 12, 8, 31, 9, 35, 10, 39, 11, 18, 12, 47, 13, 21, 14, 55, 15, 59, 16, 63, 17, 27, 18, 71, 19, 30, 20, 79, 21, 83, 22, 42, 27, 36, 24, 95, 25, 39, 26, 49, 27, 107, 28, 111, 29, 45, 30, 119, 31, 48, 32, 127, 33, 131, 34, 63
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
If n is an odd prime (A065091) then a(n) = (n + 1)/2.
If n is a power of 2 (A000079) then a(n) = 2*n - 1.
If n is a perfect number (A000396) then a(n) = 2*n - 1, assuming there are no odd perfect numbers.
The symmetric representation of sigma(n) has A001227(n) subparts.
For the definition of the "subpart" see A279387.
For a diagram with the subparts for the first 16 positive integers see A296508.
|
|
LINKS
|
|
|
EXAMPLE
|
For n = 15 the subparts of the symmetric representation of sigma(15) are [8, 7, 1, 8], the largest subpart is 8, so a(15) = 8.
|
|
MATHEMATICA
|
(* a280851[] and support function are defined in A280851 *)
a296512[n_]:=Max[a280851[n]]
|
|
CROSSREFS
|
Cf. A000079, A000203 (sum of subparts), A000225, A000396, A001227 (number of subparts), A065091, A196020, A235791, A236104, A237048,A 237270, A237271, A237591, A237593, A245092, A279387, A279391, A280850, A280851, A296508.
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|