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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). 28

%I

%S 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,

%T 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,

%U 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

%N 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).

%H Harry J. Smith, <a href="/A062068/b062068.txt">Table of n, a(n) for n = 1..1000</a>

%e d(sigma(5)) = d(6) = 4.

%t Table[DivisorSigma[0, DivisorSigma[1, n]], {n, 1, 80}] (* _Carl Najafi_, Aug 16 2011 *)

%o (PARI) for(n=1,120,print(numdiv(sigma(n))))

%o (PARI) { for (n=1, 1000, write("b062068.txt", n, " ", numdiv(sigma(n))) ) } \\ _Harry J. Smith_, Jul 31 2009]

%K nonn

%O 1,2

%A _Amarnath Murthy_, Jun 13 2001

%E Corrected and extended by _Jason Earls_, Jun 16 2001

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Last modified July 17 09:09 EDT 2019. Contains 325099 sequences. (Running on oeis4.)