A043042 Base-10 palindromes that start with 7.

7, 77, 707, 717, 727, 737, 747, 757, 767, 777, 787, 797, 7007, 7117, 7227, 7337, 7447, 7557, 7667, 7777, 7887, 7997, 70007, 70107, 70207, 70307, 70407, 70507, 70607, 70707, 70807, 70907, 71017, 71117, 71217, 71317, 71417, 71517, 71617, 71717, 71817, 71917

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• changed

Comments

Subsequence of A002113 (palindromic numbers). Union of A222727 (palindromic primes starting with a digit 7) and A222728 (palindromic composite numbers starting with a digit 7). - Jaroslav Krizek, Mar 12 2013

Links

• Jaroslav Krizek, Table of n, a(n) for n = 1..2222

Crossrefs

Cf. A002113.

Programs

Mathematica

palQ[n_Integer, base_Integer] := Module[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; Select[Range[0, 100000], IntegerDigits[#][[1]] == 7 && palQ[#, 10] &] (* T. D. Noe, Mar 12 2013 *)
Select[Range[72000],First[IntegerDigits[#]]==7&&PalindromeQ[#]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 02 2018 *)