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

1,2

Links

Table of n, a(n) for n=1..28.

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). - Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009; corrected by R. J. Mathar, Sep 16 2009

Prog

(PARI) a(n)=2*(n-2)*2^n +n*(n+1)/2+4

Crossrefs

Sequence in context: A180669 A027964 A183957 * A247557 A027937 A135026

Adjacent sequences: A078498 A078499 A078500 * A078502 A078503 A078504

Keyword

nonn,easy

Author

Benoit Cloitre, Jan 04 2003

Status

approved