A276438 a(n) = (A274647(n)-A274647(n-1)) / n.

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

Offset: 1

Author

Antti Karttunen, Sep 04 2016

Keywords

• sign

Comments

a(n) tells what k was finally used when determining the value of A274647(n), with minus sign if subtraction was chosen and with positive sign if addition was chosen.

First 1 occurs at n=1, first 2 at n=24, first 3 at n=128, first 4 at n=204, first 5 at n=17903, first 6 at n=210027.

First -1 occurs at n=4, first -2 at n=124, first -3 at n=5882.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..17903

Crossrefs

Cf. A274647.

Cf. A276439 (partial sums).

Programs

Scheme

(define (A276438 n) (/ (- (A274647 n) (A274647 (- n 1))) n))

Formula

a(n) = (A274647(n)-A274647(n-1)) / n.