A261227 - OEIS

A261227

a(n) = number of steps to reach 0 when starting from k = n^3 and repeatedly applying the map that replaces k with k - A055401(k), where A055401(k) = the number of positive cubes needed to sum to k using the greedy algorithm.

0, 1, 2, 5, 11, 20, 34, 53, 78, 109, 147, 191, 245, 307, 378, 459, 550, 653, 768, 897, 1039, 1196, 1368, 1555, 1758, 1979, 2217, 2473, 2747, 3041, 3354, 3689, 4046, 4424, 4824, 5248, 5697, 6170, 6669, 7194, 7746, 8325, 8934, 9571, 10237, 10935, 11664, 12424, 13216, 14043, 14903, 15798, 16727, 17694, 18696, 19735, 20812, 21929, 23084, 24279, 25514

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OFFSET

0,3

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..512

FORMULA

a(0) = 0, a(1) = 1; for n >= 2, a(n) = A261229(n-1) + a(n-1).

a(n) = A261226(n^3).

PROG

(Scheme) ;; Two variants, the first one using definec-macro.

(definec (A261227 n) (if (<= n 1) n (+ (A261229 (- n 1)) (A261227 (- n 1)))))

(define (A261227 n) (A261226 (* n n n)))