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A098220
a(n) = floor(sigma(sigma(p))/p) = floor(sigma(p+1)/p) = floor(A008333(n)/p), where p is the n-th prime number.
4
2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 1, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 3, 1, 2, 1, 2, 2, 1, 2, 2, 1, 2, 3, 1, 2, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 1, 1, 2, 2, 2, 3, 2, 1, 2, 2, 2, 1, 2, 1, 3, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 3, 1, 2, 2, 3, 2, 2, 1, 1, 1, 2, 2, 2, 2
OFFSET
1,1
COMMENTS
Values of these quotients are expectedly lower than ratios of A051027(n)/n.
EXAMPLE
For n = 7, the seventh prime is 17, so a(7) = floor(sigma(sigma(17))/17) = floor(sigma(18)/17) = floor(39/17) = 2.
PROG
(PARI) a(n) = my(p=prime(n)); sigma(p+1)\p; \\ Michel Marcus, Dec 23 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 25 2004
STATUS
approved