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Partial products of A024816; a(1) = a(2) = 1.
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%I #11 Sep 08 2022 08:46:18

%S 1,1,2,6,54,486,9720,204120,6531840,241678080,13050616320,

%T 652530816000,50244872832000,4069834699392000,390704131141632000,

%U 41023933769871360000,5538231058932633600000,731046499779107635200000,124277904962448297984000000

%N Partial products of A024816; a(1) = a(2) = 1.

%F a(1) = a(2) = 1; for n>2, a(n) = Product_{i=3..n} A024816(i).

%t FoldList[#1 #2 &, Table[Boole[n <= 2] + n (n + 1)/2 - DivisorSigma[1, n], {n, 19}]] (* _Michael De Vlieger_, Jan 11 2017 *)

%o (Magma) [1, 1] cat [&*[k*(k+1)/2 - SumOfDivisors(k): k in [3..n]]: n in [3..100]]

%Y Cf. A024816(n) = sum of nondivisors of n.

%Y Cf. A076664.

%K nonn

%O 1,3

%A _Jaroslav Krizek_, Jan 11 2017