OFFSET
1,1
COMMENTS
a(n) is taken to be the smallest number >= a(n-1) which is compatible with the description.
EXAMPLE
Start with 2 in row 1 and form a triangle where row n is generated from row n-1 by the rule given in the description. Then row 2 will have (2) 4's, row 3 will have (4) 6's and (4) 8's, etc.
The triangle begins:
2;
4,4;
6,6,6,6,8,8,8,8; ...
The number of terms in each row (also row sums with offset) is given by A113725: [1,2,8,56,984,87848,115679160,...].
PROG
(PARI) a=[2, 4, 4]; for(n=2, 20, for(i=1, a[n], a=concat(a, 2*n+2))); a
CROSSREFS
KEYWORD
nonn
AUTHOR
Floor van Lamoen and Paul D. Hanna, Nov 08 2005
STATUS
approved