

A052474


Construct difference array so that (1) first row begins with 1, (2) every row is monotonic increasing, (3) no number appears more than once, (4) smallest number not yet used begins a new row. Sequence gives main diagonal.


9



1, 2, 4, 7, 12, 13, 14, 15, 16, 18, 20, 21, 22, 23, 32, 35, 36, 39, 42, 48, 49, 50, 51, 53, 54, 57, 58, 59, 61, 62, 64, 66, 68, 76, 77, 78, 80, 82, 86, 87, 89, 91, 92, 93, 98, 103, 109, 110, 118, 124, 127, 128, 129, 132, 133, 135, 136, 139, 140, 141, 142, 143, 149
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OFFSET

1,2


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..150


EXAMPLE

Array begins
1 3 9 26 73 194 ...
.2 6 17 47 121 ...
. 4 11 30 74 ...
.. 7 19 44 ...
... 12 25 ...
.... 13 ...


PROG

(Haskell)
a052474 n = a056230_tabl !! (n1) !! 0
 Reinhard Zumkeller, Nov 19 2011


CROSSREFS

Cf. A057153 (first row), A057154 (numbers not used), A056230 (array), A056231, A056232, A056233, A056234.
Sequence in context: A097592 A267699 A193841 * A033054 A266186 A306673
Adjacent sequences: A052471 A052472 A052473 * A052475 A052476 A052477


KEYWORD

nice,nonn,easy


AUTHOR

Jonas Wallgren, Jul 30, 2000.


STATUS

approved



