A117331 Lexicographically earliest permutation of prime powers such that the exponents of succeeding terms increase at most by 1.

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

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: A361299 A115928 A247665 * A080612 A039261 A039201

Adjacent sequences: A117328 A117329 A117330 * A117332 A117333 A117334

Keyword

nonn,changed

Author

Reinhard Zumkeller, Mar 08 2006

Status

approved