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A073956 Palindromes whose sum of anti-divisors is palindromic. 3
1, 2, 3, 4, 5, 6, 8, 9, 242, 252, 323, 434, 727, 4774, 32223, 42024, 43234, 46864, 64946, 70607, 4855584, 4942494, 6125216, 6265626, 149939941, 188737881, 241383142, 389181983, 470212074, 27685458672, 42685658624, 45625352654, 61039793016 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A066272 for definition of anti-divisor.

Subsequence of A002113. - Michel Marcus, Aug 10 2014

LINKS

Table of n, a(n) for n=1..33.

PROG

(Python)

from itertools import chain

def is_palindrome(x):

....return x == x[::-1]

A073956 = sorted([n for n in chain(map(lambda x:int(str(x)+str(x)[::-1]), range(1, 10**2)), map(lambda x:int(str(x)+str(x)[-2::-1]), range(1, 10**3))) if is_palindrome(str(int(sum([d for d in range(2, n, 2) if n%d and not 2*n%d]))+int(sum([d for d in range(3, n, 2) if n%d and 2*n%d in [d-1, 1]]))))]) # Chai Wah Wu, Aug 09 2014

CROSSREFS

Cf. A002113, A066272, A066417.

Sequence in context: A203616 A274049 A038101 * A270193 A039266 A039205

Adjacent sequences:  A073953 A073954 A073955 * A073957 A073958 A073959

KEYWORD

base,nonn

AUTHOR

Jason Earls, Sep 03 2002

EXTENSIONS

a(21)-a(33) from Donovan Johnson, Mar 30 2010

STATUS

approved

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Last modified September 19 03:31 EDT 2021. Contains 347550 sequences. (Running on oeis4.)