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A333516
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Irregular triangle read by rows in which row n lists the first A000217(n) terms of A002260, n >= 1.
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5
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1, 1, 1, 2, 1, 1, 2, 1, 2, 3, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6
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OFFSET
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1,4
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COMMENTS
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a(n) equals the difference between n and the largest number less than n that can be expressed as the sum of the i-th triangular number and the j-th tetrahedral number for integers i < j.
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LINKS
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Table of n, a(n) for n=1..105.
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FORMULA
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a(n) = A002260(A124171(n)).
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EXAMPLE
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Triangle begins:
1;
1, 1, 2;
1, 1, 2, 1, 2, 3;
1, 1, 2, 1, 2, 3, 1, 2, 3, 4;
1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5;
1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6;
1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7;
...
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MAPLE
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T:= n-> seq([$1..i][], i=1..n):
seq(T(n), n=1..7); # Alois P. Heinz, Apr 10 2020
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CROSSREFS
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Row sums give A000292.
Right border gives A000027.
Cf. A000217, A002260, A124171.
Sequence in context: A175190 A317685 A257540 * A228202 A308972 A137900
Adjacent sequences: A333513 A333514 A333515 * A333517 A333518 A333519
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KEYWORD
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nonn,easy,tabf
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AUTHOR
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Andrew Slattery, Mar 25 2020
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STATUS
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approved
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