1,1

Table of n, a(n) for n=1..72.

F. Ellermann, Some EIS sequences based on a spiral of natural numbers.

Index entries for sequences that are permutations of the natural numbers.

7 8 9 10: ..., a(7)= 8, a(8)= 9, a(9)= 10, ...

6 1 2 11: ..., a(6)= 1, a(1)= 2, a(2)= 11, ... (see A054552, A054567).

5 4 3 12: ..., a(5)= 4, a(4)= 3, a(3)= 12, ...

n = A068226(A068225(n)). Right (left) part of middle row is A054552 (A054567).

Sequence in context: A090009 A153706 A201187 * A043080 A108199 A137904

Adjacent sequences: A068222 A068223 A068224 * A068226 A068227 A068228

nonn,easy

Frank Ellermann, Feb 22 2002

approved