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A104608
Write the natural numbers in base 4 in a triangle with k digits in the k-th row, as shown below. Sequence gives the leading diagonal.
15
1, 3, 1, 1, 1, 0, 1, 2, 1, 1, 0, 0, 2, 1, 2, 3, 1, 3, 1, 2, 2, 1, 1, 1, 2, 0, 0, 2, 1, 0, 2, 2, 2, 1, 0, 2, 0, 0, 3, 3, 2, 2, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 1, 2, 2, 3, 1, 1, 3, 2, 0, 2, 2, 1, 0, 1, 2, 2, 2, 3, 2, 2, 2, 3, 3, 3, 3, 3, 0, 0, 1, 3, 3, 2, 2, 2, 3, 3, 3, 2, 3, 0, 1, 1, 2, 1, 1, 2
OFFSET
1,2
COMMENTS
1
23
101
1121
32021
222330...
MATHEMATICA
t = Flatten[IntegerDigits[Range[1500], 4]]; t[[Table[n(n + 1)/2, {n, 105}]]]
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Mar 16 2005
STATUS
approved