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A199771 Row sums of the triangle in A199332. 9
1, 5, 12, 26, 45, 75, 112, 164, 225, 305, 396, 510, 637, 791, 960, 1160, 1377, 1629, 1900, 2210, 2541, 2915, 3312, 3756, 4225, 4745, 5292, 5894, 6525, 7215, 7936, 8720, 9537, 10421, 11340, 12330, 13357, 14459, 15600, 16820, 18081, 19425, 20812, 22286, 23805 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) = sum(A199332(n,k): 1 <= k <= n);
a(2*n-1) = A015237(n); a(2*n) = A048395(n);
a(n+1) = A200252(n).
LINKS
FORMULA
G.f. x*( 1+3*x+x^2+x^3 ) / ((1+x)^2*(x-1)^4). - R. J. Mathar, Nov 24 2011
a(n) = n*(3+2*n^2+4*n+(-1)^n))/8. - R. J. Mathar, Jun 23 2023
MATHEMATICA
LinearRecurrence[{2, 1, -4, 1, 2, -1}, {1, 5, 12, 26, 45, 75}, 50] (* Harvey P. Dale, Apr 27 2019 *)
PROG
(Haskell)
a199771 = sum . a199332_row
(PARI) a(n)=([0, 1, 0, 0, 0, 0; 0, 0, 1, 0, 0, 0; 0, 0, 0, 1, 0, 0; 0, 0, 0, 0, 1, 0; 0, 0, 0, 0, 0, 1; -1, 2, 1, -4, 1, 2]^(n-1)*[1; 5; 12; 26; 45; 75])[1, 1] \\ Charles R Greathouse IV, Jun 18 2017
CROSSREFS
Sequence in context: A294017 A367379 A212561 * A200252 A176448 A078517
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, Nov 23 2011
STATUS
approved

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Last modified February 26 22:44 EST 2024. Contains 370354 sequences. (Running on oeis4.)