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A305378 Tribonacci representation of 2n+1, written in base 10.

%I A305378 #17 Jun 13 2018 10:01:35
%S A305378 1,3,5,8,10,12,16,18,20,22,25,27,33,35,37,40,42,44,48,50,52,54,65,67,
%T A305378 69,72,74,76,80,82,84,86,89,91,97,99,101,104,106,108,128,130,132,134,
%U A305378 137,139,141,145,147,149,152,154,160,162,164,166,169,171,173,177,179,181,192,194,196,198,201
%N A305378 Tribonacci representation of 2n+1, written in base 10.
%H A305378 Robert Israel, <a href="/A305378/b305378.txt">Table of n, a(n) for n = 0..10000</a>
%p A305378 L[0]:= [0]: L[1]:= [1]:
%p A305378 for d from 2 to 10 do
%p A305378   L[d]:= map(t -> (2*t, `if`(t mod 4 <> 3, 2*t+1,NULL)), L[d-1])
%p A305378 od:
%p A305378 A003726:=map(op,[seq(L[i],i=0..10)]):
%p A305378 seq(A003726[i],i=2..nops(A003726),2); # _Robert Israel_, Jun 12 2018
%o A305378 (Python)
%o A305378 def A305378(n):
%o A305378     m, tlist, s = 2*n+1, [1,2,4], 0
%o A305378     while tlist[-1]+tlist[-2]+tlist[-3] <= m:
%o A305378         tlist.append(tlist[-1]+tlist[-2]+tlist[-3])
%o A305378     for d in tlist[::-1]:
%o A305378         s *= 2
%o A305378         if d <= m:
%o A305378             s += 1
%o A305378             m -= d
%o A305378     return s # _Chai Wah Wu_, Jun 12 2018
%Y A305378 Equals A003726(2n+1).
%Y A305378 Cf. A278038.
%K A305378 nonn,base
%O A305378 0,2
%A A305378 _N. J. A. Sloane_, Jun 12 2018
%E A305378 More terms from _Robert Israel_, Jun 12 2018