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A064550
a(1) = 2, a(n)=a(n-1)+2*Q(n)-n, n > 1 where Q = A005185.
3
1, 2, 4, 7, 9, 12, 16, 19, 23, 26, 28, 33, 37, 40, 46, 49, 53, 58, 62, 67, 71, 74, 76, 85, 89, 92, 98, 103, 107, 110, 120, 123, 125, 132, 140, 143, 147, 154, 158, 163, 169, 174, 180, 185, 189, 192, 194, 211, 211, 212, 222, 227, 227, 234, 240, 241
OFFSET
0,2
MAPLE
A064550 := proc(n) option remember; if n=0 then 1 else A064550(n-1)+2*A005185(n-1)(n) - n; fi; end;
MATHEMATICA
q[0] = q[1] = 1;
q[n_] := q[n - q[n - 1]] + q[n - q[n - 2]];
a[1] = 2;
a[n_] := a[n] = a[n - 1] + 2*(q[n] - n/2);
Table[ a[n], {n, 1, 70} ]
PROG
(ARIBAS): function a064550(maxarg: integer); var n, r, rm, q: integer; qar: array; begin qar := alloc(array, maxarg + 1); qar[0] := 1; for n := 1 to maxarg do if n < 2 then q := 1; else q := qar[n - qar[n - 1]] + qar[n - qar[n - 2]]; end; qar[n] := q; if n = 1 then r := 2; else r := rm + round(2*(q - n/2)); end; rm := r; write(r, " "); end; end; a064550(65).
(Haskell)
a064550 n = a064550_list !! n
a064550_list = 1 : 2 : zipWith3 (\a q n -> a + 2 * q - n)
(tail a064550_list) (drop 2 a005185_list) [2..]
-- Reinhard Zumkeller, May 13 2012
CROSSREFS
KEYWORD
nonn,nice,easy
AUTHOR
Roger L. Bagula, Oct 08 2001
EXTENSIONS
More terms from Vladeta Jovovic, Klaus Brockhaus and Matthew Conroy, Oct 09 2001
STATUS
approved