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A210257
Construct a triangle with centered rows in which row n contains n copies of n; form the componentwise sum of the first n rows and concatenate these decimal numbers to get a(n).
0
1, 212, 32423, 4364634, 548696845, 651081291281056, 7612101512161215101267, 87141218152016201518121478, 981614211824202520241821141689, 109181624212824302530242821241618910
OFFSET
1,2
COMMENTS
A109242 may be constructed using a similar pyramid algorithm:
....1..........a(1) = 1
...1 1.........a(2) = 111
..1 1 1........a(3) = 11211
.1 1 1 1.......a(4) = 1122211
EXAMPLE
...1................a(1) = 1
..2 2...............a(2) = 212
.3 3 3..............a(3) = 32423
4 4 4 4.............a(4) = 4364634
CROSSREFS
Sequence in context: A332121 A083962 A007942 * A239045 A262657 A079794
KEYWORD
nonn,base
AUTHOR
Dave Durgin, Mar 19 2012
EXTENSIONS
Definition edited by N. J. A. Sloane, Jan 11 2020
STATUS
approved