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%I #9 Apr 14 2017 13:06:07
%S 2,8,27,128,750,5184,41160,368640,3674160,40320000,482993280,
%T 6270566400,87697209600,1314380390400,21016195200000,357082280755200,
%U 6424604169984000,122021710626816000,2439660069310464000,51218989645824000000,1126555274886193152000,25905540583064862720000,621623493403188756480000,15538186060797648568320000
%N a(1) = 2; for n > 1, a(n) = (n-2)! * n^3.
%C In factorial base representation (A007623) the terms are written as: 10, 110, 1011, 10110, 101100, 1011000, 10110000, ... From a(3) = 27 = "1011" onward each term begins always with "1011", followed by n-3 zeros. - _Antti Karttunen_, Sep 24 2016
%H <a href="/index/Fa#facbase">Index entries for sequences related to factorial base representation</a>
%F a(1) = 2; for n > 1, a(n) = (n-2)! * n^3.
%F a(n) = n * A054119(n).
%F For n >= 3, a(n) = (n+1)! + (n-1)! + (n-2)!.
%t Join[{2},Table[(n-2)! n^3,{n,2,30}]] (* _Harvey P. Dale_, Apr 14 2017 *)
%o (Scheme, two alternatives)
%o (define (A276940 n) (if (= 1 n) 2 (* n n n (A000142 (- n 2)))))
%o (define (A276940 n) (cond ((= 1 n) 2) ((= 2 n) 8) (else (+ (A000142 (+ 1 n)) (A000142 (- n 1)) (A000142 (- n 2))))))
%Y Cf. A000142, A000578, A054119.
%Y Row 20 of A276955 (from a(3) = 27 onward).
%K nonn,base
%O 1,1
%A _Antti Karttunen_, Sep 24 2016