A083136 - OEIS

%I #21 May 09 2021 19:24:30

%S 1,2,3,4,5,6,7,8,9,11,101,111,121,131,141,151,161,171,181,191,202,313,

%T 323,333,343,353,363,373,383,393,404,515,606,727,737,747,757,767,777,

%U 787,797,808,919,929,939,949,959,969,979,989,999,1001,10001,10101,10201

%N a(n+1) is the smallest palindrome greater than a(n) and relatively prime to a(n).

%C Subsequence of A002113. - _Michel Marcus_, May 25 2014

%C Contains at most one 2k-digit number for every k, since all such palindromes are divisible by 11. - _Ivan Neretin_, Aug 12 2015

%H Giovanni Resta, <a href="/A083136/b083136.txt">Table of n, a(n) for n = 1..10000</a>

%t spal[n_]:=Module[{k=n+1},While[!PalindromeQ[k]||!CoprimeQ[k,n],k++];k]; NestList[spal,1,60] (* _Harvey P. Dale_, May 09 2021 *)

%o (PARI) ispal(n) = my(d=digits(n)); d == Vecrev(d);

%o lista(nn) = {print1(last = 1, ", "); for (n=2, nn, if (ispal(n) && gcd(n, last)== 1, print1(n, ", "); last = n;););} \\ _Michel Marcus_, Aug 12 2015

%Y Cf. A002113, A081939.

%K base,easy,nonn

%O 1,2

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 24 2003

%E More terms from _David Wasserman_, Oct 19 2004