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 A049895 a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 3. 3
 1, 1, 3, 4, 5, 13, 23, 37, 50, 136, 269, 529, 1034, 1969, 3545, 5650, 7619, 20887, 41771, 83533, 167042, 333985, 667577, 1333714, 2663747, 5312257, 10561868, 20873284, 40746839, 77515135, 139469243, 222296635, 299811770, 821920174 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS MAPLE s := proc(n) option remember; `if`(n < 1, 0, a(n) + s(n - 1)) end proc: a := proc(n) option remember; `if`(n < 4, [1, 1, 3][n],        s(n - 1) - a(-2^ceil(log[2](n - 1)) + 2*n - 2))      end proc: seq(a(n), n = 1..40); # Petros Hadjicostas, Nov 19 2019 CROSSREFS Cf. A049894 (similar with minus a(m/2)), A049942 (similar with plus a(m/2)), A049943 (similar with plus a(m)). Sequence in context: A242497 A062201 A211518 * A226117 A221173 A330138 Adjacent sequences:  A049892 A049893 A049894 * A049896 A049897 A049898 KEYWORD nonn AUTHOR EXTENSIONS Name edited by Petros Hadjicostas, Nov 19 2019 STATUS approved

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Last modified August 6 19:52 EDT 2020. Contains 336256 sequences. (Running on oeis4.)