

A248145


Consider the partition of the positive odd integers into minimal blocks such that concatenation of numbers in each block is a number of the form 3^k*prime, k>=0. Sequence lists numbers of odd integers in the blocks.


4



2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 2, 1, 1, 1, 7, 1, 1, 1, 2, 1, 1, 1, 2
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

3^m, m>=1, is of the considered form 3^k*prime, k=m1>=0, prime=3.
The first blocks of the partition are 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,...


LINKS



EXAMPLE

The 12th block of partition is 25,27,29, since we have 25=5^2, 2527=7*19^2, 252729=3^2*28081, and only the last number is of the required form. So a(12)=3.


CROSSREFS



KEYWORD

nonn,base,more


AUTHOR



STATUS

approved



