A043041 Base-10 palindromes that start with 6.

6, 66, 606, 616, 626, 636, 646, 656, 666, 676, 686, 696, 6006, 6116, 6226, 6336, 6446, 6556, 6666, 6776, 6886, 6996, 60006, 60106, 60206, 60306, 60406, 60506, 60606, 60706, 60806, 60906, 61016, 61116, 61216, 61316, 61416, 61516, 61616, 61716, 61816, 61916, 62026

Offset

1,1

Links

Jaroslav Krizek and David A. Corneth, Table of n, a(n) for n = 1..10000 (first 2222 terms from Jaroslav Krizek)

Formula

a(n) = A002113(k) iff k starts with 7 or 16. - David A. Corneth, Jun 25 2017

Mathematica

palQ[n_Integer, base_Integer] := Module[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; Select[Range[0, 100000], IntegerDigits[#][[1]] == 6 && palQ[#, 10] &] (* T. D. Noe, Mar 12 2013 *)
Select[Flatten[Table[Range[6*10^n, 7*10^n-1], {n, 0, 4}]], PalindromeQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 25 2017 *)

Prog

(PARI) nxt2113(n)={my(d=digits(n)); i=(#d+1)\2; while(i&&d[i]==9, d[i]=0; d[#d+1-i]=0; i--); if(i, d[i]++; d[#d+1-i]=d[i], d=vector(#d+1); d[1]=d[#d]=1); d}
nxt(n) = my(d = nxt2113(n)); if(d[1]==6, fromdigits(d), 6*(10^#d+1))
print1(a = 6, ", "); for (n=1, 30, print1(a = nxt(a), ", ")) \\ David A. Corneth, Jun 25 2017

Crossrefs

Intersection of A002113 and A217399.

Sequence in context: A119214 A075138 A227164 * A243719 A156237 A119142

Adjacent sequences: A043038 A043039 A043040 * A043042 A043043 A043044

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved