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A261223
a(n) = number of steps to reach 0 when starting from k = (n*n)-1 and repeatedly applying the map that replaces k with k - A053610(k), where A053610(k) = the number of positive squares that sum to k using the greedy algorithm.
9
0, 1, 3, 5, 8, 11, 14, 18, 23, 28, 34, 40, 47, 54, 61, 69, 77, 86, 96, 106, 117, 128, 140, 152, 164, 177, 190, 204, 218, 233, 248, 264, 281, 298, 316, 334, 353, 372, 391, 411, 432, 453, 474, 496, 518, 541, 564, 588, 612, 637, 663, 689, 716, 743, 771, 799, 827, 856, 886, 916, 947, 978, 1009, 1041, 1073, 1106, 1139, 1173, 1207, 1242, 1277, 1313, 1350, 1387, 1425, 1463, 1502, 1541
OFFSET
1,3
LINKS
FORMULA
a(n) = A261221((n^2)-1).
a(n) = A261222(n)-1.
MATHEMATICA
Table[-2 + Length@ NestWhileList[# - Block[{m = #, c = 1}, While[a = (# - Floor[Sqrt@ #]^2) &@ m; a != 0, c++; m = a]; c] &, (n + 1)^2, # != 0 &], {n, 0, 77}] (* Michael De Vlieger, Sep 08 2016, after Jud McCranie at A053610 *)
PROG
(Scheme, two variants, the other one using memoization-macro definec)
(definec (A261223 n) (if (= 1 n) 0 (+ (A261224 (- n 1)) (A261223 (- n 1)))))
(define (A261223 n) (A261221 (- (* n n) 1)))
CROSSREFS
One less than A261222.
Cf. also A260733, A261228.
Sequence in context: A005356 A060432 A156023 * A062009 A062484 A348450
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 12 2015
STATUS
approved