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A068818 a(n) = smallest triangular number having no digit in common with the previous term, with a(1) = 1. 1

%I #16 Dec 05 2013 19:55:13

%S 1,3,6,10,28,36,45,66,78,91,253,406,528,630,741,820,946,1035,2278,

%T 3003,4186,5050,6216,7503,8128,9045,11628,33930,41616,52003,61776,

%U 80200,93961,200028,311655,422740,511566,723003,846951,3027030,4114146,5000703,6168828

%N a(n) = smallest triangular number having no digit in common with the previous term, with a(1) = 1.

%H Jayanta Basu and T. D. Noe, <a href="/A068818/b068818.txt">Table of n, a(n) for n = 1..100</a> (first 69 terms from Jayanta Basu)

%t t = {}; p = 1; Do[If[Intersection @@ IntegerDigits /@ {x = n*(n + 1)/2, p} == {}, AppendTo[t, p]; p = x], {n, 2, 5000}]; t (* _Jayanta Basu_, Aug 07 2013 *)

%K nonn,base

%O 1,2

%A _Amarnath Murthy_, Mar 07 2002

%E Corrected and extended by _Sascha Kurz_, Mar 27 2002

%E Additional terms from _Jayanta Basu_, Aug 07 2013

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Last modified May 6 02:22 EDT 2024. Contains 372290 sequences. (Running on oeis4.)