A261230 a(n) = A261236(n) - A261237(n).

-1, 0, 1, 2, 3, 6, 12, 28, 71, 186, 494, 1317, 3478, 9045, 23265, 59856, 155779, 412413, 1108874, 3009228, 8188150, 22257484, 60462422, 164715758, 452011067, 1253176571

Offset: 0

Author

Antti Karttunen, Aug 16 2015

Keywords

• sign

Crossrefs

Cf. A261234, A261236, A261237.

Programs

Mathematica

Table[Length@ # - 2 First@ FirstPosition[#, k_ /; k != 2] + 1 &@ Map[First@ IntegerDigits[#, 3] &, #] &@ NestWhileList[# - Total@ IntegerDigits[#, 3] &, 3^(n + 1) - 1, # > 3^n - 1 &], {n, 0, 16}] (* Michael De Vlieger, Jun 27 2016, Version 10 *)

Scheme

(define (A261230 n) (- (A261236 n) (A261237 n)))

Formula

a(n) = A261236(n) - A261237(n).

Extensions

Terms a(24) & a(25) from Antti Karttunen, Jun 27 2016