a(n) = + 1 - 2 - 3 + 4 + 5 + 6 - 7 - 8 - 9 - 10 + 11 + 12 + 13 + 14 + 15 - ... + (+-1)*n, where there is one plus, two minuses, three pluses, etc. (see A002024).

A064520

a(n) = + 1 - 2 - 3 + 4 + 5 + 6 - 7 - 8 - 9 - 10 + 11 + 12 + 13 + 14 + 15 - ... + (+-1)*n, where there is one plus, two minuses, three pluses, etc. (see A002024).

Terms

    a(0) =1a(1) =-1a(2) =-4a(3) =0a(4) =5a(5) =11a(6) =4a(7) =-4a(8) =-13a(9) =-23a(10) =-12a(11) =0a(12) =13a(13) =27a(14) =42a(15) =26a(16) =9a(17) =-9a(18) =-28a(19) =-48a(20) =-69a(21) =-47a(22) =-24a(23) =0a(24) =25a(25) =51a(26) =78a(27) =106a(28) =77a(29) =47

External references