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A072363 Composite numbers whose sum of divisors is palindromic. 2
4, 81, 96, 98, 130, 146, 162, 166, 201, 205, 208, 221, 244, 274, 300, 314, 325, 333, 365, 388, 422, 438, 489, 519, 559, 633, 685, 793, 803, 1376, 1419, 1505, 1548, 1806, 1841, 2021, 2268, 2284, 2305, 2561, 2611, 2666, 2751, 2763, 2838, 2881, 2892, 2967, 3010 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

a(2) = 81: sum of divisors of 81 = 1+3+9+27+81 = 121, which is a palindrome.

MATHEMATICA

Select[Range[3000], CompositeQ[#] && PalindromeQ @ DivisorSigma[1, #] &] (* Amiram Eldar, Aug 17 2020 *)

CROSSREFS

Cf. A000203, A002113, A072362.

Sequence in context: A159063 A337053 A258981 * A272884 A053901 A017006

Adjacent sequences:  A072360 A072361 A072362 * A072364 A072365 A072366

KEYWORD

base,nonn

AUTHOR

Shyam Sunder Gupta, Jul 18 2002

EXTENSIONS

More terms from Amiram Eldar, Aug 17 2020

STATUS

approved

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Last modified March 1 23:21 EST 2021. Contains 341741 sequences. (Running on oeis4.)