|
| |
|
|
A104362
|
|
Sum of divisors of A104350(n) - 1.
|
|
4
|
|
|
|
1, 6, 12, 60, 180, 1260, 2760, 7560, 37800, 415800, 1265040, 16287864, 113538360, 567638664, 1135134000, 19298936664, 58868650320, 1113894381120, 5499724230000, 39112247205360, 423754918508832, 10054207233388032
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
2,2
|
|
|
COMMENTS
|
a(n) = A000203(A104357(n));
a(p) = A104350(p) for primes p.
|
|
|
LINKS
|
Table of n, a(n) for n=2..23.
R. Zumkeller, Products of largest prime factors of numbers <= n
|
|
|
MAPLE
|
A000142 := proc(n) RETURN(n!) ; end: A006530 := proc(n) local i, t1, t2, t3, t4; if n = 1 then RETURN(1) ; else t1 := numtheory[divisors](n); t2 := convert(t1, list); t3 := sort(t2); t4 := nops(t3); for i from 1 to t4 do if isprime(t3[t4+1-i]) then RETURN(t3[t4+1-i]); fi; od; RETURN(1); fi ; end: A104350 := proc(n) local k, resul ; resul := 1 ; for k from 1 to n do resul := resul*A006530(k) ; od ; RETURN(resul) ; end: A104357 := proc(n) A104350(n)-1 ; end: A104362 := proc(n) numtheory[sigma](A104357(n)) ; end: for n from 2 to 30 do printf("%d, ", A104362(n)) ; od ; - R. J. Mathar, Oct 30 2006
|
|
|
CROSSREFS
|
Cf. A104361, A104370.
Sequence in context: A093901 A117762 A178957 * A123900 A103972 A121735
Adjacent sequences: A104359 A104360 A104361 * A104363 A104364 A104365
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Reinhard Zumkeller, Mar 06 2005
|
|
|
EXTENSIONS
|
Corrected and extended by R. J. Mathar, Oct 30 2006
|
|
|
STATUS
|
approved
|
| |
|
|
