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A281577
Irregular triangle read by rows: T(n, k) = A281576(n) modulo p^2, where p is the k-th prime factor of A281576(n) with p < sqrt(A281576(n)).
0
28204, 17161560961, 2451293172821355028751076998879853, 1409441895293467096954080352837, 1385195550582, 17782786311867894562037823351528977990025091057921642664123352687840735480821116989430796689072791
OFFSET
1,1
COMMENTS
The question whether T(n, k) = 0 for any values of n and k is an open problem (see Ribenboim p. 64, open problem (3)).
REFERENCES
P. Ribenboim, The Little Book of Bigger Primes, Springer Verlag, 1991.
EXAMPLE
Triangle T(n, k) starts
28204
17161560961
2451293172821355028751076998879853
1409441895293467096954080352837
1385195550582, T(5, 2)
Note: T(5, 2) is not displayed here due to its size. The term can be seen in the Data section.
PROG
(PARI) a152155(n) = centerlift(Mod(3, 2^(2^n)+1)^(2^(2^n-1)))
row(n) = my(i=0, k=1); while(1, if(a152155(k)!=-1, i++); if(i==n, forprime(p=1, sqrtint(2^(2^k)+1), if(Mod(2, p)^(2^k)==-1, print1(lift(Mod(2, p^2)^(2^k))+1, ", ")))); k++)
trianglerows(n) = for(k=1, n, row(k); print(""))
CROSSREFS
Sequence in context: A253753 A203832 A237246 * A134123 A234087 A049052
KEYWORD
nonn,tabf
AUTHOR
Felix Fröhlich, Jan 24 2017
STATUS
approved