This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A038399 #16 Apr 06 2024 07:53:04
%S A038399 1,11,211,3211,53211,853211,13853211,2113853211,342113853211,
%T A038399 55342113853211,8955342113853211,1448955342113853211,
%U A038399 2331448955342113853211,3772331448955342113853211,6103772331448955342113853211,9876103772331448955342113853211
%N A038399 Concatenate first n nonzero Fibonacci numbers in reverse order.
%D A038399 Mihaly Bencze [Beneze], L. Tutescu, Some Notions and Questions in Number Theory, Sequence 7.
%H A038399 Reinhard Zumkeller, <a href="/A038399/b038399.txt">Table of n, a(n) for n = 1..96</a>
%t A038399 Module[{nn=20,fibs},fibs=Fibonacci[Range[nn]];Table[FromDigits[ Flatten[ IntegerDigits/@ Reverse[Take[fibs,n]]]],{n,nn}]] (* _Harvey P. Dale_, Aug 30 2016 *)
%o A038399 (Haskell)
%o A038399 a038399 n = a038399_list !! (n-1)
%o A038399 a038399_list = h "" $ tail a000045_list where
%o A038399 h xs (f:fs) = (read ys :: Integer) : h ys fs
%o A038399 where ys = show f ++ xs
%o A038399 -- _Reinhard Zumkeller_, Mar 01 2014
%o A038399 (PARI) a(n) = my(t=fibonacci(n)); forstep(k=n-1, 1, -1, t=t*10^#Str(fibonacci(k))+fibonacci(k)); t; \\ _Michel Marcus_, Apr 06 2024
%Y A038399 Cf. A000045, A000422, A019523.
%K A038399 nonn,base,easy,less
%O A038399 1,2
%A A038399 M. I. Petrescu (mipetrescu(AT)yahoo.com)
%E A038399 More terms from Andrew Gacek (andrew(AT)dgi.net), Feb 21 2000
%E A038399 Offset changed by _Reinhard Zumkeller_, Mar 01 2014
%E A038399 More terms from _Harvey P. Dale_, Aug 30 2016