A261913 The palindromic order of n (defined in Comments).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2

Offset: 0

Author

N. J. A. Sloane, Sep 10 2015

Keywords

• nonn
• base

Comments

Order 1: palindromes (A002113);

Order 2: not order 1 but is the sum of two palindromes (A261907);

Order 3: not order 1 or 2, but n - previous_palindrome(n) (i.e., n - A261914(n)) gives a number of order 2 (A261910);

Order 4: not order 1, 2, or 3, but subtracting previous_palindrome(previous_palindrome(n)) gives a number of order 2 (A261911);

Order 5: not orders 1, 2, 3, or 4 (A261912).

Links

• N. J. A. Sloane, Table of n, a(n) for n = 0..20000

Crossrefs

Cf. A002113, A261423, A261907, A261910, A261911, A261912, A261914.

Closely related to A261675. See also A088601.

Formula

a(n) = A088601(n). - R. J. Mathar, Feb 14 2023