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A319080 Sequence, read by rows, encoding an infinite sequence of diamond-shaped arrays of nonnegative integers (see example). 0
0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 2, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 2, 1, 0, 0, 1, 2, 3, 2, 1, 0, 0, 1, 2, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 2, 1, 0, 0, 1, 2, 3, 2, 1, 0, 0, 1, 2, 3, 4, 3, 2, 1, 0, 0, 1, 2, 3, 2, 1, 0, 0, 1, 2, 1, 0, 0, 1, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,13

COMMENTS

The sum of each figure corresponds to A005900;

Figure 1:

0 = 0;

Figure 2:

0+0+1+0+0 = 1;

Figure 3:

0+0+1+0+0+1+2+1+0+0+1+0+0 = 6;

Figure n:

0+0+1+0+0+1+2+1+0+...+n+...0+1+2+1+0+0+1+0+0 = A005900(n).

LINKS

Table of n, a(n) for n=0..84.

EXAMPLE

Figure 1 has just 0. Figure 2 would look like a 1 surrounded by 0's. Figure 3 would look like a 2 surrounded by 1's surrounded by 0's, etc.

Read by rows, the sequence starts:

Figure 1: 0;

                     0

Figure 2: 0, 0, 1, 0, 0;

                     0

                   0 1 0

                     0

Figure 3: 0, 0, 1, 0, 0, 1, 2, 1, 0, 0, 1, 0, 0;

                     0

                   0 1 0

                 0 1 2 1 0

                   0 1 0

                     0

Figure 4: 0, 0, 1, 0, 0, 1, 2, 1, 0, 0, 1, 2, 3, 2, 1, 0, 0, 1, 2, 1, 0, 0, 1, 0, 0;

                     0

                   0 1 0

                 0 1 2 1 0

               0 1 2 3 2 1 0

                 0 1 2 1 0

                   0 1 0

                     0

...

MATHEMATICA

f[n_] := Join[#, Rest@ Reverse@ #] &@ Range[0, n]; Array[Flatten[f /@ f@ #] &, 5, 0] // Flatten (* Michael De Vlieger, Sep 10 2018 *)

CROSSREFS

Cf. A001477, A005900.

Sequence in context: A115079 A286562 A185644 * A025435 A304685 A186714

Adjacent sequences:  A319077 A319078 A319079 * A319081 A319082 A319083

KEYWORD

nonn,tabf

AUTHOR

Kritsada Moomuang, Sep 09 2018

STATUS

approved

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Last modified January 26 23:05 EST 2020. Contains 331289 sequences. (Running on oeis4.)