A185969 Let S be the sequence of power towers built of 2 and 3 sorted by their height and for equal heights - in lexicographic order: 2, 3, 2^2, 2^3, 3^2, 3^3, 2^2^2, 2^2^3 etc. A(n) = the permutation of indexes which reorders S by magnitude.

1, 2, 3, 4, 5, 7, 6, 11, 8, 9, 12, 13, 15, 23, 10, 14, 19, 27, 16, 24, 17, 25, 20, 28, 21, 29, 31, 47, 39, 55, 18, 26, 22, 30, 35, 51, 43, 59, 32, 48, 40, 56, 33, 49, 41, 57, 36, 52, 44, 60, 37, 53, 45, 61, 63, 95, 79, 111, 71, 103, 87, 119

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..14335

Vladimir Reshetnikov, 2-3 sequence puzzle, SeqFan list, Mar 18 2015

Index entries for sequences that are permutations of the natural numbers

Example

a(6) =  7; tower(7)  = 2^2^2 = 2^4 =  16.
a(7) =  6; tower(6)  = 3^3   =        27.
a(8) = 11; tower(11) = 3^2^2 = 3^4 =  81.
a(9) =  8; tower(8)  = 2^2^3 = 2^8 = 256.

Crossrefs

Cf. A032810, A248907, A256179, A256231.

Sequence in context: A288870 A283194 A254498 * A369281 A266637 A370496

Adjacent sequences: A185966 A185967 A185968 * A185970 A185971 A185972

Keyword

nonn,look

Author

Vladimir Reshetnikov, Feb 07 2011

Extensions

More terms from Alois P. Heinz, Apr 05 2011

Status

approved