A072032 a(n) = gcd(2^n, reverse(2^n)) = gcd(2^n, A004086(2^n)) = A055483(2^n).

2, 4, 8, 1, 1, 2, 1, 4, 1, 1, 2, 8, 2, 1, 1, 4, 1, 2, 1, 1, 2, 2, 2, 1, 1, 16, 1, 2, 1, 1, 4, 4, 2, 1, 1, 2, 1, 8, 1, 1, 8, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 8, 4, 1, 1, 1, 1, 1, 8, 1, 1, 16, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 8, 1, 1, 1, 1, 1, 1, 8, 1, 2, 2, 1, 1, 1, 1, 1, 1, 16, 1, 8, 1, 1

Offset

1,1

Links

Indranil Ghosh, Table of n, a(n) for n = 1..31180

Example

n=12: a(12) = gcd(4096,6904) = 8.

Mathematica

nd[x_, y_] := 10*x+y tn[x_] := Fold[nd, 0, x] red[x_] := Reverse[IntegerDigits[x]] Table[GCD[2^w, tn[red[2^w]]], {w, 1, 128}]

Crossrefs

Cf. A004086, A055483, A071686.

Sequence in context: A097625 A371133 A010743 * A365814 A023104 A133145

Adjacent sequences: A072029 A072030 A072031 * A072033 A072034 A072035

Keyword

nonn,less,base

Author

Labos Elemer, Jun 07 2002

Status

approved