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CONTINUANT transform of {sigma(n)}, 1, 3, 4, 7, 6, 12, ... (A000203).
1

%I #7 Aug 06 2013 13:01:48

%S 1,4,17,123,755,9183,74219,1122468,14666303,265115922,3196057367,

%T 89754722198,1259762168139,30324046757534,729036884348955,

%U 22630467461575139,408077451192701457,15937651063976931962,319161098730731340697,13420703797754693241236,429781682626880915060249

%N CONTINUANT transform of {sigma(n)}, 1, 3, 4, 7, 6, 12, ... (A000203).

%H Alois P. Heinz, <a href="/A071138/b071138.txt">Table of n, a(n) for n = 1..200</a>

%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

%p with(numtheory):

%p a:= proc(n) option remember; `if`(n<0, 0,

%p `if`(n=0, 1, sigma(n) *a(n-1) +a(n-2)))

%p end:

%p seq(a(n), n=1..30); # _Alois P. Heinz_, Aug 06 2013

%Y Cf. A000203.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Jun 11 2002