A261233 - OEIS

A261233

a(n) = number of steps to reach 0 when starting from k = (3^n)-1 and repeatedly applying the map that replaces k with k - (sum of digits in base-3 representation of k).

0, 1, 3, 8, 20, 49, 123, 319, 849, 2294, 6250, 17112, 47013, 129605, 358838, 998805, 2796093, 7869800, 22251147, 63141639, 179701239, 512744599, 1466635089, 4205423895, 12087339723, 34816804310, 100469592521, 290336059740, 839932833290, 2432050970420, 7047731703137, 20440131344750, 59334695322383, 172409162871823, 501489513690423, 1460214792034791

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..35.

FORMULA

a(0) = 0; for n >= 1, a(n) = A261234(n-1) + a(n-1).

a(n) = A261231((3^n)-1).

a(n) = A261232(n)-1.

PROG

(Scheme, two variants)

(definec (A261233 n) (if (zero? n) n (+ (A261234 (- n 1)) (A261233 (- n 1)))))