%I #4 Mar 30 2012 18:40:30
%S 1,3,4,8,11,12,19,22,23,25,36,44,47,48,73,84,92,95,96,140,165,176,184,
%T 187,188,268,316,341,352,360,363,364,517,609,657,682,693,701,704,705,
%U 998,1174,1266,1314,1339,1350,1358,1361,1362,1923,2264,2440,2532,2580
%N First differences of Lucas 4-step numbers.
%C Lucas 4-step numbers are also known as "Tetranacci Lucas numbers" or "Tetranacci numbers with different initial conditions" in A073817. Primes in this sequence are A113295. In this sequence are: 13340261 = 11 * 19 * 29 * 31 * 71 is a product of 5 distinct 2-digit primes; 95550683 = 269 * 593 * 599 is a product of 3 distinct 3-digit primes.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Lucasn-StepNumber.html">Lucas n-Step Number.</a>
%H Noe, T. D. and Post, J. V., <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL8/Noe/noe5.html">Primes in Fibonacci n-step and Lucas n-Step Sequences."</a> J. Integer Seq. 8, Article 05.4.4, 2005.
%F {a(n)} = { | A073817(i) - A073817(j) | such that i>=j }
%e a(0) = 1 because A073817(0)-A001644(2) = 4 - 3 = 1.
%e a(1) = 3 because A073817(3)-A001644(0) = 7 - 4 = 3.
%e a(2) = 4 because A073817(3)-A001644(2) = 7 - 3 = 4.
%e a(3) = 8 because A073817(4)-A001644(3) = 15 - 7 = 8.
%e a(122) = 70000 because A073817(17)-A001644(3) = 70007 - 7 = 70000.
%Y Cf. A000040, A073817, A113188-A113194, A113238, A113239, A113244, A113293, A113295.
%K easy,nonn
%O 1,2
%A _Jonathan Vos Post_, Oct 23 2005