%I #18 Jun 17 2017 03:04:36

%S 36,136,236,336,436,536,636,736,836,936,1036,1136,1236,1336,1436,1536,

%T 1636,1736,1836,1936,2036,2136,2236,2336,2436,2536,2636,2736,2836,

%U 2936,3036,3136,3236,3336,3436,3536,3636,3736,3836,3936,4036,4136,4236,4336

%N Numbers n such that n and 2^n end with the same two digits.

%C 2^36=68719476736 hence 36 is in the sequence.

%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).

%F a(n) = 36+100(n-1).

%F a(n) = 2*a(n-1)-a(n-2). G.f.: 4*x*(9+16*x)/(1-x)^2. [_Colin Barker_, Dec 01 2012]

%o (PARI) isok(n) = (2^n - n) % 100 == 0; \\ _Michel Marcus_, Nov 23 2013

%Y Cf. A064541.

%Y Subsequence of A067844.

%K easy,nonn,base

%O 1,1

%A _Benoit Cloitre_, Mar 07 2002