A135020 Each natural number is followed by its reversal.

1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 1, 11, 11, 12, 21, 13, 31, 14, 41, 15, 51, 16, 61, 17, 71, 18, 81, 19, 91, 20, 2, 21, 12, 22, 22, 23, 32, 24, 42, 25, 52, 26, 62, 27, 72, 28, 82, 29, 92, 30, 3, 31, 13, 32, 23, 33, 33, 34, 43, 35, 53, 36, 63, 37, 73, 38, 83, 39, 93

Offset

1,3

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Formula

a(n) = (n+1)/2 for n = odd, a(n) = A004086(n/2) for n = even.

Crossrefs

Cf. A004086.

Sequence in context: A176841 A176814 A088461 * A242681 A034888 A320467

Adjacent sequences: A135017 A135018 A135019 * A135021 A135022 A135023

Keyword

easy,nonn,base,look

Author

Rolf Pleisch, Feb 10 2008

Status

approved