A129285 a(n) = A129151(n) / 27.

3, 4, 8, 20, 44, 92, 188, 380, 856, 2148, 5024, 17616, 58768, 176320, 755904, 3305920, 13885184, 69634816, 348174336, 2385273856, 14652403712, 102566830080, 849285738496, 6035962949632, 44017806979072, 308166534991872, 2380768960708608, 23410894780694528

Offset: 0

Author

Reinhard Zumkeller, Apr 07 2007

Keywords

• nonn

Crossrefs

Cf. A129284 (essentially the same), A129283 (n + n'), A129286, A051674, A129150, A090636 (trajectory of 15 under arithmetic derivative A003415).

Programs

Haskell

a129285 n = a129151 n `div` 27  -- Reinhard Zumkeller, Nov 01 2013 [Moved here from A129284, first erroneous line deleted. - M. F. Hasler, Nov 27 2019]

Formula

a(n+1) = A129283(a(n)), a(0) = 3.

a(n) = A129284(n+1). - Eric M. Schmidt, Oct 22 2013

Thus a(n) = A129150(n+1) / 4 = A090636(n+3) / 4. - M. F. Hasler, Nov 27 2019