A078501 a(n) = Sum_{k=1..n^2} A078446(k).
1, 7, 26, 78, 211, 537, 1312, 3112, 7217, 16443, 36934, 82002, 180319, 393325, 852092, 1835148, 3932317, 8388783, 17825986, 37748950, 79692011, 167772417, 352321816, 738197808, 1543504201, 3221225827, 6710886782, 13958644122
Offset: 1
Keywords
Programs
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PARI
a(n)=2*(n-2)*2^n +n*(n+1)/2+4
Formula
a(n) = 2*(n-2)*2^n + n*(n+1)/2 + 4
G.f.: x*(1-4*x^2+4*x^3)/((2*x-1)^2 * (1-x)^3) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]
Extensions
G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.