A317335 a(n) = A317332(n) - 8*n.

1, 1, -2, 1, 1, -2, -2, 1, 1, 1, -2, -2, 1, -2, -2, 1, 1, 1, -2, 1, 1, -2, -2, -2, 1, 1, -2, -2, 1, -2, -2, 1, 1, 1, -2, 1, 1, -2, -2, 1, 1, 1, -2, -2, 1, -2, -2, -2, 1, 1, -2, 1, 1, -2, -2, -2, 1, 1, -2, -2, 1, -2, -2

Offset: 1

Author

A.H.M. Smeets, Jul 26 2018

Keywords

• sign

Links

• A.H.M. Smeets, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A317331, A317332, A317333, A317336.

Programs

Python

n, f, i, p, q = 1, 1, 0, 0, 1
while i < 1000000:
    i, p, q = i+1, p*10, q*10
    if i == f:
        p, n = p+1, n+1
        f = f*n
n, a, j = 0, 0, 0
while p%q > 0:
    a, f, p, q = a+1, p//q, q, p%q
    if f == 8:
        n = n+1
        print(n, a-1-8*n)

Formula

a(4*n-3) = 1, a(4*n-1) = -2, a(2*n) = a(n) for n > 0.

abs(a(n)+1) = A014710(n-1).

abs(a(n)) = A014709(n-1).