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Numbers k such that the sum of the first k odd composites is palindromic.
4

%I #19 Aug 29 2022 21:44:44

%S 1,12,25,61,108,211,1344,2339,10539,78409,283181,1748747,1795423,

%T 2386702,2819089,179101605,1923088106,2822581688,7794689270,

%U 17381011919,25635268093,28780043265,97973526253

%N Numbers k such that the sum of the first k odd composites is palindromic.

%C Sequence is 9 + 15 + 21 + 25 + 27 + 33 + ... + z. For values of z see A058849.

%H Patrick De Geest, <a href="http://www.worldofnumbers.com/firstpal.htm#sfn4">Palindromic Sums</a>

%Y Cf. A058849, A058850, A262044.

%K nonn,base,more

%O 1,2

%A _Patrick De Geest_, Dec 15 2000

%E a(20) from _Donovan Johnson_, Sep 01 2012

%E a(21)-a(23) from _Chai Wah Wu_, Dec 06 2019