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%I #7 Aug 17 2024 23:10:40
%S 1,9,153,5049,328185,42335865,10880317305,5581602777465,
%T 5721142846901625,11722621693301429625,48027581077455957173625,
%U 393489971767596657123509625,6447333187412071226968705205625,211272661218306162036537500883125625
%N a(n) = (1/30)*A028361(n) for n>=3.
%C a(n+1)/a(n) is an integer for n>=0, so (a(n)) is a divisibility sequence.
%F a(n) = (1/30)(s**t)(n), where s = A000012 = (1,1,1,...), t = A000079 = (1,2,4,8,16,...), and ** denotes obverse convolution, as in A374848.
%F a(n) = A060202(n+1)/180. - _Hugo Pfoertner_, Aug 07 2024
%t s[n_] := 1; t[n_] := 2^n;
%t u[n_] := Product[s[k] + t[n - k], {k, 0, n}]
%t (1/30) Table[u[n], {n, 2, 20}]
%Y Cf. A000012, A000079, A060202, A374848.
%K nonn
%O 3,2
%A _Clark Kimberling_, Aug 05 2024