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A343902
T(n, k) is the k-th prime p such that (p-1)|A000010(n); irregular array read by rows.
2
2, 2, 2, 3, 2, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 5, 7, 2, 3, 2, 3, 5, 2, 3, 5, 2, 3, 5, 2, 3, 2, 3, 7, 2, 3, 5, 2, 3, 5, 7, 2, 3, 2, 3, 2, 3, 5, 2, 3, 5, 11, 2, 3, 5, 7, 2, 3, 7, 2, 3, 5, 7, 2, 3, 5, 2, 3, 5, 2, 3, 7, 11, 2, 3, 5, 2, 3, 5, 11, 2, 3, 5
OFFSET
3,1
EXAMPLE
The irregular array T starts as follows:
2
2
2, 3
2
2, 3
2, 3
2, 3
2, 3
2, 3
2, 3
2, 3, 5, 7
2, 3
2, 3, 5
2, 3, 5
2, 3, 5
2, 3
2, 3, 7
2, 3, 5
2, 3, 5, 7
2, 3
2, 3
2, 3, 5
2, 3, 5, 11
2, 3, 5, 7
2, 3, 7
2, 3, 5, 7
2, 3, 5
2, 3, 5
2, 3, 7, 11
2, 3, 5
PROG
(PARI) row(n) = my(e=eulerphi(n)); forprime(p=2, e, if(e%(p-1)==0, print1(p, ", "))); print("")
array(rows) = for(x=3, rows+2, row(x))
array(10) \\ Print upper 10 rows of the array
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Felix Fröhlich, May 03 2021
STATUS
approved