A088180 - OEIS

%I #16 Sep 04 2014 17:22:13

%S 1,5,19,112,368,2161,7033,41140,133730,781884,2541197,14856466,

%T 48283738,282274893,917394087,5363229225,17430497086,101901374524,

%U 331179473681,1936126175213,6292410089388,36786397511512,119555791973835,698941553280624,2271560048351176

%N a(n) is the number of numbers m < 10^n for which there is at least one k such that k + reverse(k) = m.

%C Number of terms of A067030 below 10^n.

%C a(16)-a(18) are based on two empirically detected recursive formulas. [_Lars Blomberg_, Nov 25 2011]

%H Hiroaki Yamanouchi, <a href="/A088180/b088180.txt">Table of n, a(n) for n = 0..100</a>

%H Lars Blomberg, <a href="/A088180/a088180.pdf">A short investigation of the sequence and derivation of the recursive formulas</a>

%H <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a>

%e a(1) = 5 since 0, 2, 4, 6, 8 are the terms of A067030 which are smaller than 10^1.

%Y Cf. A067030.

%K nonn,base

%O 0,2

%A _Klaus Brockhaus_, Sep 22 2003

%E a(9)-a(10) from _Donovan Johnson_, Sep 22 2009

%E a(11)-a(18) from _Lars Blomberg_, Dec 19 2011

%E a(19)-a(24) from _Hiroaki Yamanouchi_, Sep 04 2014