A107322 English name for number and its reverse have the same number of letters.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 14, 22, 33, 34, 35, 38, 41, 43, 44, 45, 48, 53, 54, 55, 58, 66, 67, 69, 76, 77, 79, 83, 84, 85, 88, 96, 97, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 111, 112, 113, 115, 118, 121, 122, 123, 124, 125, 126, 127, 128, 129, 131, 132

Offset: 0

Author

David W. Wilson, May 21 2005

Keywords

• base
• nonn
• word

Comments

Obviously includes all palindromes (A002113).

Examples

			35 is in sequence because 35 ("thirty-five") and 53 ("fifty-three") each have 10 letters in English (dashes not counted).
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A002113, A004086, A005589.

Programs

Mathematica

Select[Range[0,132],Length[Select[Characters[IntegerName[#,"Words"]],LetterQ]]==Length[Select[Characters[IntegerName[FromDigits[Reverse[IntegerDigits[#]]],"Words"]],LetterQ]]&] (* James C. McMahon, Feb 12 2024 *)

Python

from num2words import num2words
def n2w(n):
  map = {ord(c): None for c in "-, "}
  return num2words(n).replace(" and", "").translate(map)
def ok(n): return len(n2w(n)) == len(n2w(int(str(n)[::-1])))
print([k for k in range(133) if ok(k)]) # Michael S. Branicky, Feb 12 2024

Extensions

10 inserted by James C. McMahon, Feb 12 2024