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A062068
a(n) = d(sigma(n)), where d(k) is the number of divisors function (A000005) and sigma(k) is the sum of divisor function (A000203).
31
1, 2, 3, 2, 4, 6, 4, 4, 2, 6, 6, 6, 4, 8, 8, 2, 6, 4, 6, 8, 6, 9, 8, 12, 2, 8, 8, 8, 8, 12, 6, 6, 10, 8, 10, 4, 4, 12, 8, 12, 8, 12, 6, 12, 8, 12, 10, 6, 4, 4, 12, 6, 8, 16, 12, 16, 10, 12, 12, 16, 4, 12, 8, 2, 12, 15, 6, 12, 12, 15, 12, 8, 4, 8, 6, 12, 12, 16, 10, 8, 3, 12, 12, 12, 12, 12
OFFSET
1,2
LINKS
EXAMPLE
d(sigma(5)) = d(6) = 4.
MATHEMATICA
Table[DivisorSigma[0, DivisorSigma[1, n]], {n, 1, 80}] (* Carl Najafi, Aug 16 2011 *)
PROG
(PARI) for(n=1, 120, print(numdiv(sigma(n))))
(PARI) { for (n=1, 1000, write("b062068.txt", n, " ", numdiv(sigma(n))) ) } \\ Harry J. Smith, Jul 31 2009
CROSSREFS
Sequence in context: A291290 A006047 A285712 * A328219 A328879 A130542
KEYWORD
nonn,easy
AUTHOR
Amarnath Murthy, Jun 13 2001
EXTENSIONS
Corrected and extended by Jason Earls, Jun 16 2001
STATUS
approved