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

0,3

Comments

Obviously includes all palindromes (A002113).

Links

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

Example

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

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 *)

Prog

(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

Crossrefs

Cf. A002113, A004086, A005589.

Sequence in context: A065448 A254656 A211408 * A194975 A299441 A069751

Adjacent sequences: A107319 A107320 A107321 * A107323 A107324 A107325

Keyword

base,nonn,word

Author

David W. Wilson, May 21 2005

Extensions

10 inserted by James C. McMahon, Feb 12 2024

Status

approved