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%I #35 Dec 12 2021 11:55:02
%S 10,22,34,46,58,70,82,94,106,118,130,142,154,166,178,190,202,214,226,
%T 238,250,262,274,286,298,310,322,334,346,358,370,382,394,406,418,430,
%U 442,454,466,478,490,502,514,526,538,550,562,574,586,598,610,622,634
%N a(n) = 12n + 10.
%C Exponents e such that x^e + x^2 - 1 is reducible.
%C If Y is a 4-subset of an (2n+1)-set X then, for n>=3, a(n-2) is the number of 3-subsets of X having at least two elements in common with Y. - _Milan Janjic_, Dec 16 2007
%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>.
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A030132(a(n)) = 9. - _Reinhard Zumkeller_, Jul 04 2007
%F G.f.: 2*(5 + x)/(1 - x)^2. - _Stefano Spezia_, May 09 2021
%F Sum_{n>=0} (-1)^n/a(n) = Pi/12 - sqrt(3)*log(2 + sqrt(3))/12. - _Amiram Eldar_, Dec 12 2021
%t Range[10, 1000, 12] (* _Vladimir Joseph Stephan Orlovsky_, May 29 2011 *)
%o (PARI) a(n)=12*n+10 \\ _Charles R Greathouse IV_, Jul 10 2016
%Y Cf. A008594, A017533, A017545, A017593, A030132.
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_
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