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

1,2

Comments

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

Links

Table of n, a(n) for n=1..50.

Example

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.

Prog

(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

Crossrefs

Cf. A000203, A088000.

Sequence in context: A135709 A263043 A028980 * A096841 A029963 A259389

Adjacent sequences: A183105 A183106 A183107 * A183109 A183110 A183111

Keyword

nonn,base

Author

Jaroslav Krizek, Dec 25 2010

Status

approved