A183108 Numbers m such that sum of divisors of m and sum of palindromic divisors of m are both palindromic.

1, 2, 3, 4, 5, 7, 43, 130, 146, 166, 201, 205, 211, 221, 241, 244, 251, 271, 274, 281, 314, 325, 365, 388, 422, 433, 443, 463, 489, 519, 559, 633, 685, 793, 827, 857, 877, 887, 1841, 2021, 2111, 2221, 2284, 2305, 2441, 2551, 2561, 2666, 2751, 2881

Offset: 1

Author

Jaroslav Krizek, Dec 25 2010

Keywords

• nonn
• base

Comments

Numbers m such that A000203(m) and A088000(m) are both palindromic.

Examples

			a(8) = 130, divisors of 130: 1, 2, 5, 10, 13, 26, 65, 130; palindromic divisors of 130: 1, 2, 5; A000203(130) = 252, A088000(130) = 8; both numbers are palindromic.
		

Crossrefs

Cf. A000203, A088000.

Programs

Sage

is_palindrome = lambda n, base=10: n.str(base) == n.str(base)[::-1]
A000203 = sigma
A088000 = lambda n: sum(d for d in divisors(n) if is_palindrome(d))
is_A183108 = lambda n: is_palindrome(A000203(n)) and is_palindrome(A088000(n)) # D. S. McNeil, Dec 28 2010