A029965 Palindromic in bases 9 and 10.

0, 1, 2, 3, 4, 5, 6, 7, 8, 191, 282, 373, 464, 555, 646, 656, 6886, 25752, 27472, 42324, 50605, 626626, 1540451, 1713171, 1721271, 1828281, 1877781, 1885881, 2401042, 2434342, 2442442, 2450542, 3106013, 3114113, 3122213, 3163613

Offset

1,3

Links

Robert G. Wilson v and Ray Chandler, Table of n, a(n) for n = 1..66 (terms < 10^18, first 52 terms from Robert G. Wilson v)

P. De Geest, Palindromic numbers beyond base 10

Mathematica

NextPalindrome[n_] := Block[{l = Floor[ Log[10, n] + 1], idn = IntegerDigits[n]}, If[ Union[idn] == {9}, Return[n + 2], If[l < 2, Return[n + 1], If[ FromDigits[ Reverse[ Take[idn, Ceiling[l/2]] ]] FromDigits[ Take[idn, -Ceiling[l/2]]], FromDigits[ Join[ Take[idn, Ceiling[l/2]], Reverse[ Take[idn, Floor[l/2]] ]]], idfhn = FromDigits[ Take[idn, Ceiling[l/2]]] + 1; idp = FromDigits[ Join[ IntegerDigits[idfhn], Drop[ Reverse[ IntegerDigits[idfhn]], Mod[l, 2]] ]]] ]]]; palQ[n_Integer, base_Integer] := Block[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; l = {0}; a = 0; Do[a = NextPalindrome[a]; If[ palQ[a, 9], AppendTo[l, a]], {n, 10000}]; l (* Robert G. Wilson v, Sep 30 2004 *)
pQ[n_, k_]:=Reverse[x=IntegerDigits[n, k]]==x; t={}; Do[If[pQ[n, 10] && pQ[n, 9], AppendTo[t, n]], {n, 3.2*10^6}]; t (* Jayanta Basu, May 25 2013 *)
Select[Range[0, 10^5],
PalindromeQ[#] && # == IntegerReverse[#, 9] &] (* Robert Price, Nov 09 2019 *)

Crossrefs

Cf. A007632, A007633, A029961, A029962, A029963, A029964, A029804, A029966, A029967, A029968, A029969, A029970, A029731, A097855, A099165.

Sequence in context: A037336 A037443 A073790 * A004881 A004892 A365822

Adjacent sequences: A029962 A029963 A029964 * A029966 A029967 A029968

Keyword

nonn,base

Author

Patrick De Geest

Status

approved