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A171868 First differences of A171865.

%I A171868 #18 May 22 2025 10:21:35
%S A171868 1,2,2,5,2,5,3,4,6,5,6,3,3,5,4,3,4,3,6,9,3,5,3,6,3,4,5,6,5,4,4,5,4,4,
%T A171868 6,4,4,6,6,5,6,4,4,9,3,3,6,4,3,10,3,4,4,6,4,5,3,3,6,6,7,3,5,4,5,4,6,6,
%U A171868 6,5,4,6,4,4,6,4,5,4,7,3,4,5,4,8,10,3,5,5,6,3,8,4,4,6,7,6,6,10,4,4,8,3,4,4
%N A171868 First differences of A171865.
%H A171868 N. J. A. Sloane, <a href="/A171868/b171868.txt">Table of n, a(n) for n = 1..15098</a>
%o A171868 (Haskell)
%o A171868 a171868 n = a171868_list !! (n-1)
%o A171868 a171868_list = zipWith (-) (tail a171865_list) a171865_list
%o A171868 -- _Reinhard Zumkeller_, Oct 31 2011
%o A171868 (Python)
%o A171868 A181391_list, A171868_list, l = [0, 0], [1], 0
%o A171868 for n in range(1, 10**4):
%o A171868     for m in range(n-1, -1, -1):
%o A171868         if A181391_list[m] == A181391_list[n]:
%o A171868             A181391_list.append(n-m)
%o A171868             break
%o A171868     else:
%o A171868         A181391_list.append(0)
%o A171868         A171868_list.append(n-l)
%o A171868         l = n # _Chai Wah Wu_, Jan 02 2015
%Y A171868 Cf. A181391, A171865, A171888, A171887.
%Y A171868 Identical to A171889 except for the leading 0. - Jan Ritsema van Eck (j.ritsemavaneck(AT)planet.nl), Oct 19 2010
%K A171868 nonn
%O A171868 1,2
%A A171868 _N. J. A. Sloane_, Oct 18 2010