A091677 - OEIS

%I #7 Jul 11 2015 00:51:40

%S 469892287,318,68346,66349,269237759,272353,110333,1082314,4279,3903,

%T 1049659,290,1210,4334,275436,4199,73784,2082046,5046,4212653,1052467,

%U 4768988414,1073998008,1051069,1058784,719,795,799,265038,119810013

%N a(n) = smallest non-palindromic k such that the base-4 Reverse and Add! trajectory of k is palindrome-free and joins the trajectory of A091675(n).

%C a(1), a(5), a(22), a(23) and a(30) are conjectural; it is not yet ensured that they are minimal.

%C a(n) >= A091675(n); a(n) = A091675(n) iff the trajectory of A091675(n) is palindrome-free, i.e., A091675(n) is also a term of A075421.

%C a(n) determines a 1-1-mapping from the terms of A091675 to the terms of A075421, the inverse of the mapping determined by A091676.

%C The 1-1 property of the mapping depends on the conjecture that the base-4 Reverse and Add! trajectory of each term of A091675 contains only a finite number of palindromes (cf. A091680).

%C Base-4 analog of A089494.

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

%e A091675(2) = 3, the trajectory of 3 joins the trajectory of 318 = A075421(2) at 20966400, so a(2) = 318. A091675(4) = 22, the trajectory of 22 joins the trajectory of 66349 = A075421(130) at 600785, so a(4) = 66349.

%Y Cf. A075421, A091675, A091676, A091680, A089494.

%K nonn,base

%O 1,1

%A _Klaus Brockhaus_, Jan 28 2004