A285741 a(0) = 1; a(2*n) = a(n), a(2*n+1) = a(n) + R(a(n)), where R() is the digit reversal.

1, 2, 2, 4, 2, 4, 4, 8, 2, 4, 4, 8, 4, 8, 8, 16, 2, 4, 4, 8, 4, 8, 8, 16, 4, 8, 8, 16, 8, 16, 16, 77, 2, 4, 4, 8, 4, 8, 8, 16, 4, 8, 8, 16, 8, 16, 16, 77, 4, 8, 8, 16, 8, 16, 16, 77, 8, 16, 16, 77, 16, 77, 77, 154, 2, 4, 4, 8, 4, 8, 8, 16, 4, 8, 8, 16, 8, 16, 16, 77, 4, 8, 8, 16, 8, 16, 16, 77, 8, 16, 16

Offset: 0

Author

Ilya Gutkovskiy, Apr 25 2017

Keywords

• nonn
• base

Examples

			a(0) = 1;
a(1) = a(2*0+1) = a(0) + R(a(0)) = 1 + 1 = 2;
a(2) = a(2*1) = a(1) = 2;
a(3) = a(2*1+1) = a(1) + R(a(1)) = 2 + 2 = 4;
a(4) = a(2*2) = a(2) = 2;
a(5) = a(2*2+1) = a(2) + R(a(2)) = 2 + 2 = 4, etc.
		

Links

• Michael Gilleland, Some Self-Similar Integer Sequences
• Index entries for sequences related to Reverse and Add!

Crossrefs

Cf. A001127 (records), A004086, A056964.

Programs

Mathematica

a[0] = 0; a[n_] := If[EvenQ[n], a[n/2], a[(n - 1)/2] + FromDigits[Reverse[IntegerDigits[a[(n - 1)/2]]]] ]; Table[a[n], {n, 0, 90}]