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A325821 Multiplication table for carryless product i X j in base 3 for i >= 1 and j >= 1, read by antidiagonals. 4
1, 2, 2, 3, 1, 3, 4, 6, 6, 4, 5, 8, 9, 8, 5, 6, 7, 12, 12, 7, 6, 7, 3, 15, 16, 15, 3, 7, 8, 5, 18, 11, 11, 18, 5, 8, 9, 4, 21, 24, 13, 24, 21, 4, 9, 10, 18, 24, 19, 21, 21, 19, 24, 18, 10, 11, 20, 27, 23, 26, 9, 26, 23, 27, 20, 11, 12, 19, 30, 36, 19, 15, 15, 19, 36, 30, 19, 12, 13, 24, 33, 40, 45, 12, 13, 12, 45, 40, 33, 24, 13, 14, 26, 36, 44, 50, 54, 11, 11, 54, 50, 44, 36, 26, 14 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is table A325820 without the zero row and column. See there for more comments.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..5050; the first 100 antidiagonals of array

Index entries for sequences related to carryless arithmetic

EXAMPLE

The array begins as:

   1,  2,  3,  4,  5,  6,  7,  8,   9,  10,  11,  12, ...

   2,  1,  6,  8,  7,  3,  5,  4,  18,  20,  19,  24, ...

   3,  6,  9, 12, 15, 18, 21, 24,  27,  30,  33,  36, ...

   4,  8, 12, 16, 11, 24, 19, 23,  36,  40,  44,  48, ...

   5,  7, 15, 11, 13, 21, 26, 19,  45,  50,  52,  33, ...

   6,  3, 18, 24, 21,  9, 15, 12,  54,  60,  57,  72, ...

   7,  5, 21, 19, 26, 15, 13, 11,  63,  70,  68,  57, ...

   8,  4, 24, 23, 19, 12, 11, 16,  72,  80,  76,  69, ...

   9, 18, 27, 36, 45, 54, 63, 72,  81,  90,  99, 108, ...

  10, 20, 30, 40, 50, 60, 70, 80,  90, 100,  83, 120, ...

  11, 19, 33, 44, 52, 57, 68, 76,  99,  83,  91, 132, ...

  12, 24, 36, 48, 33, 72, 57, 69, 108, 120, 132, 144, ...

PROG

(PARI)

up_to = 105;

A325820sq(b, c) = fromdigits(Vec(Pol(digits(b, 3))*Pol(digits(c, 3)))%3, 3);

A325821list(up_to) = { my(v = vector(up_to), i=0); for(a=1, oo, for(col=1, a, i++; if(i > up_to, return(v)); v[i] = A325820sq(col, (a-(col-1))))); (v); };

v325821 = A325821list(up_to);

A325821(n) = v325821[n];

CROSSREFS

Cf. A003991, A091257, A325820.

Sequence in context: A089913 A257522 A059897 * A341607 A303719 A299595

Adjacent sequences:  A325818 A325819 A325820 * A325822 A325823 A325824

KEYWORD

nonn,base,tabl

AUTHOR

Antti Karttunen, May 22 2019

STATUS

approved

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Last modified May 26 13:59 EDT 2022. Contains 354092 sequences. (Running on oeis4.)