

A066686


Array T(i,j) read by antidiagonals, where T(i,j) is the concatenation of i and j (1<=i, 1<=j).


2



11, 12, 21, 13, 22, 31, 14, 23, 32, 41, 15, 24, 33, 42, 51, 16, 25, 34, 43, 52, 61, 17, 26, 35, 44, 53, 62, 71, 18, 27, 36, 45, 54, 63, 72, 81, 19, 28, 37, 46, 55, 64, 73, 82, 91, 110, 29, 38, 47, 56, 65, 74, 83, 92, 101, 111, 210, 39, 48, 57, 66, 75, 84, 93, 102, 111
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OFFSET

1,1


COMMENTS

The element at T(i,j) is the {(i+j1)(i+j2)/2 + i}th element read in the sequence.


LINKS

Table of n, a(n) for n=1..66.
Alexander Bogomolny, What is a number?
Boris Putievskiy, Transformations [Of] Integer Sequences And Pairing Functions, arXiv preprint arXiv:1212.2732, 2012.


EXAMPLE

The array begins
11 12 13 14 15 16 17 18 19 110 ...
21 22 23 24 25 26 27 28 29 210 ...
31 32 33 34 35 36 37 38 39 310 ...
41 42 43 44 45 46 47 48 49 410 ...


MATHEMATICA

a = {}; Do[ a = Append[a, ToExpression[ StringJoin[ ToString[k], ToString[n  k]]]], {n, 2, 13}, {k, 1, n  1} ]; a


CROSSREFS

Sequence in context: A057303 A121979 A109372 * A125887 A107478 A153146
Adjacent sequences: A066683 A066684 A066685 * A066687 A066688 A066689


KEYWORD

easy,nonn,tabl,base


AUTHOR

Robert G. Wilson v, Jan 11 2002


STATUS

approved



