login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A051896 a(n) = smallest palindrome > a(n-1) such that a(1)*a(2)*...*a(n) + 1 is prime with a(1) = 2. 4

%I #16 Apr 18 2022 19:18:26

%S 2,3,5,6,9,55,66,77,88,161,191,313,484,494,525,747,3223,3993,11711,

%T 13431,13731,18881,19691,21012,21112,22422,24242,34443,35353,41114,

%U 44244,44844,46664,52225,52925,53935,58385,59895,60806,64146,71917

%N a(n) = smallest palindrome > a(n-1) such that a(1)*a(2)*...*a(n) + 1 is prime with a(1) = 2.

%H Chai Wah Wu, <a href="/A051896/b051896.txt">Table of n, a(n) for n = 1..200</a>

%t nxt[{t_,a_}]:=Module[{k=a+1},While[(!PalindromeQ[k])||CompositeQ[k*t+1],k++];{t*k,k}]; NestList[nxt,{2,2},40][[All,2]] (* _Harvey P. Dale_, Apr 18 2022 *)

%Y Cf. A046966, A051934, A051954.

%Y Subsequence of A002113.

%K easy,nice,nonn,base

%O 1,1

%A _Felice Russo_, Dec 21 1999

%E Initial conditions added to description by _Chai Wah Wu_, Apr 16 2021

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 23 21:15 EDT 2024. Contains 375396 sequences. (Running on oeis4.)