A029962 Palindromic in bases 5 and 10.

0, 1, 2, 3, 4, 6, 88, 252, 282, 626, 676, 1221, 15751, 18881, 10088001, 10400401, 27711772, 30322303, 47633674, 65977956, 808656808, 831333138, 831868138, 836131638, 836181638, 2512882152, 2596886952, 2893553982, 6761551676

Offset

1,3

Links

Robert G. Wilson v, Table of n, a(n) for n = 1..79

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, 5], AppendTo[l, a]], {n, 200000}]; l (* Robert G. Wilson v, Sep 30 2004 *)
Select[Range[0, 10^5],
PalindromeQ[#] && # == IntegerReverse[#, 5] &] (* Robert Price, Nov 09 2019 *)

Crossrefs

Cf. A007632, A007633, A029961, A029963, A029964, A029965, A029966, A029967, A029968, A029969, A029970.

Sequence in context: A084811 A051856 A135236 * A259388 A049010 A340100

Adjacent sequences: A029959 A029960 A029961 * A029963 A029964 A029965

Keyword

nonn,base

Author

Patrick De Geest

Status

approved