A341330 a(n) = Sum_{k=1..n} (-k)^(k+1).

1, -7, 74, -950, 14675, -265261, 5499540, -128718188, 3358066213, -96641933787, 3041786442934, -103951418936138, 3833424966763151, -151734670591049073, 6416673685121841552, -288731231494230984304, 13774353220573494006705, -694460992134764182350927

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Mathematica

Accumulate[(-#)^(#+1)&/@Range[17]]

Prog

(PARI) a(n) = sum(i=1, n, (-i)^(i+1));
(Python)
sum = 0
for i in range(1, 20):
    sum += (-i)**(i+1)
    print(sum, end = ", ")

Crossrefs

Cf. A007778, A062815.

Sequence in context: A000901 A295245 A365844 * A266305 A098118 A097821

Adjacent sequences: A341327 A341328 A341329 * A341331 A341332 A341333

Keyword

sign

Author

John H. Chakkour, Feb 09 2021

Status

approved