

A117331


Lexicographically earliest permutation of prime powers such that the exponents of succeeding terms increase at most by 1.


4



1, 2, 3, 4, 5, 7, 9, 8, 11, 13, 17, 19, 23, 25, 27, 16, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 125, 81, 32, 64, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227
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OFFSET

1,2


COMMENTS

A025474(A095874(a(n+1)))  A025474(A095874(a(n))) <= 1;
A117332(n) = A095874(a(n));
a(A117333(n)) = A000961(n).


LINKS

Table of n, a(n) for n=1..63.
Eric Weisstein's World of Mathematics, Prime Power


EXAMPLE

a(13)..a(16): 23,5^2,3^3,2^4;
a(38)..a(43): 113,11^2,5^3,3^4,2^5,2^6;
a(239)..a(248): 1367,37^2,11^3,5^4,3^5,3^6,2^7,2^8,2^9,2^10.


CROSSREFS

Sequence in context: A105362 A115928 A247665 * A080612 A039261 A039201
Adjacent sequences: A117328 A117329 A117330 * A117332 A117333 A117334


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Mar 08 2006


STATUS

approved



