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A271873 Square array A(n, k) read by antidiagonals downwards: smallest base-n Fermat pseudoprime with k distinct prime factors for k, n >= 2. 1
341, 561, 91, 11305, 286, 15, 825265, 41041, 435, 124, 45593065, 825265, 11305, 561, 35 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

The array A(n, k) starts as follows:

   k  =  2    3     4        5         6

n = 2: 341  561 11305   825265  45593065

n = 3:  91  286 41041   825265 130027051

n = 4:  15  435 11305   418285  30534805

n = 5: 124  561 41041  2203201  68800501

n = 6:  35 1105 25585   682465  12306385

LINKS

Table of n, a(n) for n=2..16.

PROG

(PARI) minpsp(n, k) = forcomposite(c=1, , if(Mod(n, c)^(c-1)==1, if(omega(c)==k, return(c))))

a(n, k) = for(x=2, n, for(y=2, k, print1(minpsp(x, y), ", ")); print(""))

a(6, 6) \\ print array up to n = 6, k = 6

CROSSREFS

Cf. A007011 (row n=2), A271874.

Sequence in context: A025353 A025345 A253038 * A001567 A178723 A210993

Adjacent sequences:  A271870 A271871 A271872 * A271874 A271875 A271876

KEYWORD

nonn,tabl,more

AUTHOR

Felix Fröhlich, Apr 16 2016

STATUS

approved

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Last modified April 26 04:55 EDT 2019. Contains 322469 sequences. (Running on oeis4.)