A085946 - OEIS

%I #18 May 01 2024 16:12:59

%S 1,2,3,23,17,7,59,11,257,11257,13,1125713,43708571,19,9,199,9199,43,

%T 487,43487,39,228881,811,1973,41,197341,51,379,191,126397,21,731,31,

%U 57,77,53,7753,79,70489,346543,121,346543121,47,37,1579,101,526367,5343493

%N a(1) = 1, a(2) = 2 and a(n) = smallest number not included earlier that divides the concatenation a(n-2), a(n-1).

%C 2 is the only even member. No member is divisible by 5. - _David Wasserman_, Feb 14 2005

%C Is this sequence finite? The base 2, base 3 and base 5 variants are finite, with 42514, 64 and 2786 terms respectively. - _Rémy Sigrist_, Oct 19 2019

%H Rémy Sigrist, <a href="/A085946/b085946.txt">Table of n, a(n) for n = 1..10000</a>

%H Rémy Sigrist, <a href="/A085946/a085946.gp.txt">PARI program for A085946</a>

%e 3, 23, 17 are three successive terms and 17 divides 323. Similarly 7 divides 2317.

%o (PARI) \\ See Links section.

%K base,nonn

%O 1,2

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 14 2003

%E More terms from _David Wasserman_, Feb 14 2005