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A276575
After a(0)=0, the first differences of A276573.
6
0, 3, 3, 2, 3, 4, 1, 2, 3, 3, 3, 3, 2, 3, 3, 2, 3, 2, 3, 3, 2, 3, 3, 4, 1, 3, 3, 2, 3, 3, 2, 3, 2, 3, 2, 3, 3, 3, 3, 3, 3, 4, 3, 2, 3, 3, 3, 2, 3, 3, 2, 3, 4, 1, 3, 2, 3, 3, 3, 2, 2, 3, 3, 3, 2, 3, 3, 4, 3, 3, 3, 3, 3, 2, 3, 4, 3, 3, 3, 3, 2, 3, 3, 4, 2, 3, 4, 3, 2, 3, 3, 4, 1, 3, 2, 3, 3, 3, 2, 3, 2, 3, 3, 3, 2, 3, 3, 2, 2, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 2, 3
OFFSET
0,2
LINKS
Burkard Polster, Root 2 and the deadly Marching Squares, Mathologer video (2015)
FORMULA
a(n) = A002828(A276573(n)).
a(0) = 0; for n >= 1, a(n) = A276573(n) - A276573(n-1).
Other identities.
For all n >= 1, a(A260731(A132592(n))) = a(A260733(A001541(n))) = 2. [This is implied by the fact observed in the Polster video. Of course 2's occur at other points too.]
PROG
(Scheme, two alternatives)
(define (A276575 n) (A002828 (A276573 n)))
(define (A276575 n) (if (zero? n) n (- (A276573 n) (A276573 (- n 1)))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 07 2016
STATUS
approved