A105808 Slowest increasing and self-describing sequence: first 2 digits are prime digits, followed by 3 composite digits, then 4 prime digits, then 6 composite digits, then 8 prime, then 2 composite, then 2 prime, etc.

2, 3, 4, 6, 8, 22, 23, 44, 46, 48, 52, 53, 55, 57, 64, 72, 84, 222, 444, 452, 524, 644, 722, 723, 844, 852, 2222, 2244, 4442, 5444, 6422, 7444, 8422, 22444, 44222, 52224, 64444

Offset

2,1

Comments

No 0's or 1's are allowed in the sequence. "Prime digits" are 2 3 5 7 and "composite" are 4 6 8 9.

Links

Table of n, a(n) for n=2..38.

Example

2 3 4 6 8 22 23 44 46 48 52 53 55 57 64 72 ...
^ ^ - - - ^^ ^^ -- -- -- ^^ ^^ ^^ ^^ -- ^^
.2....3.....4.......6.........8.......2..2
pri..comp..pri.....comp......pri....com..pri

Crossrefs

Sequence in context: A333681 A084074 A144722 * A124058 A274423 A118080

Adjacent sequences: A105805 A105806 A105807 * A105809 A105810 A105811

Keyword

base,easy,nonn

Author

Eric Angelini, May 05 2005

Status

approved