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Composite numbers where the sum of the smallest prime factor and the largest prime factor is an odd composite.
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%I #10 Aug 02 2024 11:39:21

%S 14,26,28,38,42,46,52,56,62,70,74,76,78,84,86,92,94,98,104,106,112,

%T 114,122,124,126,130,134,138,140,146,148,152,156,158,166,168,172,178,

%U 182,184,186,188,190,194,196,206,208,210,212,218,222,224,226,228,230,234

%N Composite numbers where the sum of the smallest prime factor and the largest prime factor is an odd composite.

%e 14 is in the sequence as 14=2*7 and 2+7=9, an odd composite; 60 is not, as 60=2^2*3*5 and 2+5 is 7, not composite.

%t Select[Range[240], CompositeQ[#] && CompositeQ[c = Min[First/@FactorInteger[#]] + Max[First/@FactorInteger[#]]] && OddQ[c] &] (* _Stefano Spezia_, Aug 02 2024 *)

%Y Cf. A002808.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Jan 04 2009

%E Definition and examples simplified by _D. S. McNeil_, Dec 10 2009

%E Corrected and extended by _D. S. McNeil_, Dec 10 2009