A307799 a(0) = 0, a(1) = 3; a(n) = rev(a(n-1))*a(n-1) + a(n-2), where rev = digit reversal (A004086).

0, 3, 9, 84, 4041, 5673648, 48020423368761, 806086788756824484462571572, 221815145293562950532110825781341443907408910699844537

Offset: 0

Author

Ilya Gutkovskiy, Apr 29 2019

Keywords

• nonn
• base

Comments

The next term is too large to include.

Examples

			+---+--------------+---------------------+------------------+
| n | a(n)/a(n+1)  | Continued fraction  |      Comment     |
+---+--------------+---------------------+------------------+
| 1 |    3/9       | [0; 3]              |    3 = rev(a(1)) |
+---+--------------+---------------------+------------------+
| 2 |    9/84      | [0; 9, 3]           |    9 = rev(a(2)) |
+---+--------------+---------------------+------------------+
| 3 |   84/4041    | [0; 48, 9, 3]       |   48 = rev(a(3)) |
+---+--------------+---------------------+------------------+
| 4 | 4041/5673648 | [0; 1404, 48, 9, 3] | 1404 = rev(a(4)) |
+---+--------------+---------------------+------------------+
		

Crossrefs

Cf. A001040, A004086, A058182.

Programs

Mathematica

a[n_] := a[n] = FromDigits[Reverse[IntegerDigits[a[n - 1]]]] a[n - 1] + a[n - 2]; a[0] = 0; a[1] = 3; Table[a[n], {n, 0, 8}]