A261221 - OEIS

A261221

a(n) = number of steps to reach 0 when starting from k = n and repeatedly applying the map that replaces k with k - A053610(k), where A053610(k) = the number of positive squares needed to sum to k using the greedy algorithm.

0, 1, 1, 1, 2, 2, 2, 2, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 17, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 21, 22, 22, 22, 23, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29

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OFFSET

0,5

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..10000

FORMULA

a(0) = 0; for n >= 1, a(n) = 1 + a(A260740(n)).

PROG

(Scheme, with memoization-macro definec)

(definec (A261221 n) (if (zero? n) n (+ 1 (A261221 (A260740 n)))))

CROSSREFS

Cf. A260740, A261222, A261223, A261224.