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A120456 Antidiagonal triangular version of the modulo 15 prime multiplication table past n=3. 0
1, 2, 2, 4, 4, 4, 7, 8, 8, 7, 8, 14, 1, 14, 8, 11, 1, 13, 13, 1, 11, 13, 7, 2, 4, 2, 7, 13, 14, 11, 14, 11, 11, 14, 11, 14 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

This modulo 15 of prime digit endings is important because it gives even odd prime types that appear in pairs: {1,4},{2,13},{7,8},{11,14}

LINKS

Table of n, a(n) for n=0..35.

FORMULA

b[n]={1, 2, 4, 7, 8, 11, 13, 14} T[n,m]=Mod[b[n]*b[m],15] a(n) = T[n,m]: antidiagonal form

EXAMPLE

Array looks like:

1, 2, 4, 7, 8, 11, 13, 14

2, 4, 8, 14, 1, 7, 11, 13

4, 8, 1, 13, 2, 14, 7, 11

7, 14, 13, 4, 11, 2, 1, 8

8, 1, 2, 11, 4, 13, 14, 7

11, 7, 14, 2, 13, 1, 8, 4

13, 11, 7, 1, 14, 8, 4, 2

14, 13, 11, 8, 7, 4, 2, 1

MATHEMATICA

Table[Mod[Prime[n], 15], {n, 1, 50}] a = {1, 2, 4, 7, 8, 11, 13, 14} b = Table[Mod[a[[n]]*a[[m]], 15], {n, 1, 8}, {m, 1, 8}] c = Table[Table[b[[n, l - n]], {n, 1, l - 1}], {l, 1, Dimensions[b][[1]] + 1}] Flatten[c]

CROSSREFS

Sequence in context: A062570 A108514 A317419 * A115383 A219156 A210036

Adjacent sequences:  A120453 A120454 A120455 * A120457 A120458 A120459

KEYWORD

nonn,tabf,fini

AUTHOR

Roger L. Bagula, Jun 23 2006

STATUS

approved

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Last modified June 22 21:29 EDT 2021. Contains 345393 sequences. (Running on oeis4.)