OFFSET
0,3
COMMENTS
Through the so-called "pyramidalization" process a given nonnegative integer is decomposed into its digits, which are "reassembled" afterwards by concatenating each level of the pyramid (separately, from left to right) and subsequently concatenating these results, from the base to the top.
The number of digits of the resulting number is the triangular number t(d) where d is the number of digits in the original number n.
LINKS
Filipi R. de Oliveira, Table of n, a(n) for n = 0..9999
FORMULA
a(n) = n for 0 <= n <= 9;
a(n) = 10*n + |floor(n/10) - (n mod 10)| for 10 <= n <= 99.
EXAMPLE
a(1248) = 1248124121:
1 --> 1
1 2 --> 1.2
1 2 4 --> 1.2.4
1 2 4 8 --> 1.2.4.8 -->> 1248.124.12.1 --> 1248124121
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Filipi R. de Oliveira, Apr 02 2014
STATUS
approved