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A057153
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 first row of array.
10
1, 3, 9, 26, 73, 194, 485, 1150, 2617, 5779, 12497, 26653, 56355, 118545, 248605, 520365, 1087853, 2272770, 4748677, 9930475, 20800122, 43658310, 91836751, 193549010, 408449129, 862455193, 1820771343, 3840569196, 8089327515
OFFSET
1,2
COMMENTS
This is the limit of the family of sequences starting with A005228, A037257, A037260. Adjoin next free number as the first element in a new level of differences unless it would produce a duplicate in which case ignore.
LINKS
FORMULA
Row sums of triangle A133544. - Gary W. Adamson, Sep 14 2007
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)
a057153 n = a056230_tabl !! (n-1) !! (n-1)
-- Reinhard Zumkeller, Nov 19 2011
CROSSREFS
Cf. A057154 (numbers not used), A052474 (main diagonal), A056230 (array). See also A005228, A037257, A037260, A057267, A056231, A056232, A056233, A056234.
Cf. A133544.
Cf. A200379 (first differences).
Sequence in context: A054963 A291733 A118046 * A084787 A121190 A054447
KEYWORD
nice,nonn,easy
AUTHOR
Jonas Wallgren, Jul 30 2000
EXTENSIONS
More terms from Rob Speer (rob(AT)twcny.rr.com) and Loren Merritt, Aug 14 2000
STATUS
approved