A261232 a(n) = number of steps to reach 0 when starting from k = 3^n and repeatedly applying the map that replaces k with k - (sum of digits in base-3 representation of k).

1, 2, 4, 9, 21, 50, 124, 320, 850, 2295, 6251, 17113, 47014, 129606, 358839, 998806, 2796094, 7869801, 22251148, 63141640, 179701240, 512744600, 1466635090, 4205423896, 12087339724, 34816804311, 100469592522, 290336059741, 839932833291, 2432050970421, 7047731703138, 20440131344751, 59334695322384, 172409162871824, 501489513690424

Offset

0,2

Links

Table of n, a(n) for n=0..34.

Formula

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

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

a(n) = 1 + A261233(n).

Prog

(Scheme, two variants)
(definec (A261232 n) (if (zero? n) 1 (+ (A261234 (- n 1)) (A261232 (- n 1)))))
(define (A261232 n) (A261231 (A000244 n)))

Crossrefs

One more than A261233.

Cf. A000244, A261231.

Cf. also A213710.

Sequence in context: A318008 A199410 A091600 * A176334 A257386 A048285

Adjacent sequences: A261229 A261230 A261231 * A261233 A261234 A261235

Keyword

nonn

Author

Antti Karttunen, Aug 13 2015

Extensions

Terms from a(24) onward added from the output of Hiroaki Yamanouchi's program by Antti Karttunen, Aug 16 2015

Status

approved