A276438 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,24

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

FORMULA

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

PROG

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

CROSSREFS

Cf. A274647.

Cf. A276439 (partial sums).

Sequence in context: A113120 A154843 A062557 * A338274 A210960 A339095

Adjacent sequences: A276435 A276436 A276437 * A276439 A276440 A276441

KEYWORD

sign

AUTHOR

Antti Karttunen, Sep 04 2016

STATUS

approved