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a(n) = tau(n)^sigma(n), where tau(n) = A000005(n) = the number of divisors of n and sigma(n) = A000203(n) = the sum of divisors of n.
5

%I #12 Jan 23 2014 00:20:28

%S 1,8,16,2187,64,16777216,256,1073741824,1594323,68719476736,4096,

%T 6140942214464815497216,16384,281474976710656,281474976710656,

%U 4656612873077392578125,262144,2227915756473955677973140996096,1048576,481229803398374426442198455156736

%N a(n) = tau(n)^sigma(n), where tau(n) = A000005(n) = the number of divisors of n and sigma(n) = A000203(n) = the sum of divisors of n.

%H Jaroslav Krizek, <a href="/A236285/b236285.txt">Table of n, a(n) for n = 1..100</a>

%F a(n) = A000005(n)^A000203(n).

%e a(4) = tau(4)^sigma(4) = 3^7 = 2187.

%t Table[DivisorSigma[0, n]^DivisorSigma[1, n], {n, 1000}]

%o (PARI) s=[]; for(n=1, 20, s=concat(s, sigma(n, 0)^sigma(n))); s \\ _Colin Barker_, Jan 22 2014

%Y Cf. A000005 (tau(n)), A000203 (sigma(n)), A062758 (n^tau(n)), A217872 (sigma(n)^n), A236284 (tau(n)^n), A236286.

%K nonn

%O 1,2

%A _Jaroslav Krizek_, Jan 21 2014

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Last modified September 21 03:08 EDT 2024. Contains 376079 sequences. (Running on oeis4.)