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A262682 Even bisection of A262680. 4
0, 0, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 0, 0, 2, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Number of perfect squares (A000290) encountered before zero is reached when starting from k = 2n and repeatedly applying the map that replaces k by k - d(k), where d(k) is the number of divisors of k (A000005). This count includes n itself if it is a square, but excludes the zero.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..10082

FORMULA

a(n) = A262680(2*n).

PROG

(Scheme) (define (A262682 n) (A262680 (+ n n)))

CROSSREFS

Cf. A000005, A000290, A010052, A049820, A155043, A262677, A262680, A262681.

Sequence in context: A160498 A089800 A079208 * A318983 A318982 A069851

Adjacent sequences:  A262679 A262680 A262681 * A262683 A262684 A262685

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 03 2015

STATUS

approved

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Last modified September 18 15:48 EDT 2020. Contains 337169 sequences. (Running on oeis4.)