A129286 a(n) = A129152(n) / 5^5, where A129152 is the trajectory of 5^6 under A003415, the arithmetic derivative.

5, 6, 11, 12, 28, 60, 152, 388, 780, 2036, 4076, 8156, 16316, 32636, 66232, 169612, 339228, 1244808, 4856004, 14568120, 56648484, 190791072, 866874960, 4084880112, 16342519392, 73816544592, 305811402048, 1732931293824, 10145637246528, 52715820454848

Offset: 0

Author

Reinhard Zumkeller, Apr 07 2007

Keywords

• nonn

Crossrefs

Cf. A129284, A129285, A051674.

Programs

Haskell

a129286 n = a129286_list !! n
a129286_list = iterate a129283 5  -- Reinhard Zumkeller, Nov 01 2013

Formula

a(n+1) = A129283(a(n)), a(0) = 5.

a(n) = A090635(n+3) / 4, i.e., the trajectory of 20 under A003415, divided by the common factor 4. - M. F. Hasler, Nov 27 2019