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A quarter-square shaped (A002620) staircase array distributing the frequency of objects counted by A047970.
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%I #4 Mar 31 2012 13:23:37

%S 1,1,1,1,2,1,1,1,3,2,4,2,2,1,4,3,8,7,9,5,5,1,1,5,4,13,14,23,20,25,16,

%T 14,7,2,1,1,6,5,19,23,44,49,71,65,75,60,48,32,18,6,1,1,7,6,26,34,73,

%U 94,154,172,232,234,249,228,195,145,101,59,27,9,2

%N A quarter-square shaped (A002620) staircase array distributing the frequency of objects counted by A047970.

%e The array begins:

%e 1..1..1..1..1..1..1....

%e ...1..2..3..4..5..6....

%e ......1..2..3..4..5....

%e ......1..4..8.13.19....

%e where the fourth row counts the ordered partitions of type 221^k and type 41^k since (1 3 6 10 15 ...) + (0 1 2 3 4 ...) yields the required result.

%K nonn,tabf

%O 1,5

%A _Alford Arnold_, Dec 26 2003