A249856 - OEIS

A249856

Let z = A084937: a(n) = number of odd numbers <= z(n) that are != z(k) for k=1..n-1 and not coprime to z(n-1) and z(n-2).

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 2, 0, 0, 0, 0, 0, 1, 0, 1, 2, 0, 2, 3, 0, 0, 2, 0, 1, 2, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 2, 4, 0, 2, 3, 0, 0, 4, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0

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OFFSET

1,19

COMMENTS

a(n) = A249777(n) - A249857(n).

LINKS

Table of n, a(n) for n=1..86.

PROG

(Haskell)

a249856 = sum . map (flip mod 2) . (uss !!)

uss = [] : [] : [] : f 2 1 [3..] where

f x y zs = g zs [] where