A236434 Table whose n-th row lists the prime factors of the n-th Giuga number A007850(n).

2, 3, 5, 2, 3, 11, 13, 2, 3, 7, 41, 2, 3, 11, 17, 59, 2, 3, 11, 23, 31, 47057, 2, 3, 7, 43, 3041, 4447, 2, 3, 7, 59, 163, 1381, 775807, 2, 3, 7, 71, 103, 67213, 713863, 2, 3, 7, 71, 103, 61559, 29133437, 2, 3, 11, 23, 31, 47137, 28282147, 3892535183, 2, 3, 11, 23, 31, 47059, 2259696349, 110725121051, 2, 3, 7, 43, 1831, 138683, 2861051, 1456230512169437

Offset

1,1

Comments

It is unknown whether there are infinitely many Giuga numbers or any odd ones.

See A007850 for other comments, references, links, etc.

For prime factors of primary pseudoperfect numbers, see A236433; of terms in Sylvester's sequence, see A126263.

Links

M. F. Hasler, Table of n, a(n) for n = 1..73

Example

30 = 2 * 3 * 5.
858 = 2 * 3 * 11 * 13.
1722 = 2 * 3 * 7 * 41.
66198 = 2 * 3 * 11 * 17 * 59.
2214408306 = 2 * 3 * 11 * 23 * 31 * 47057.
24423128562 = 2 * 3 * 7 * 43 * 3041 * 4447.
432749205173838 = 2 * 3 * 7 * 59 * 163 * 1381 * 775807.
14737133470010574 = 2 * 3 * 7 * 71 * 103 * 67213 * 713863.
550843391309130318 = 2 * 3 * 7 * 71 * 103 * 61559 * 29133437.
244197000982499715087866346 = 2 * 3 * 11 * 23 * 31 * 47137 * 28282147 * 3892535183.
554079914617070801288578559178 = 2 * 3 * 11 * 23 * 31 * 47059 * 2259696349 * 110725121051.
1910667181420507984555759916338506 = 2 * 3 * 7 * 43 * 1831 * 138683 * 2861051 * 1456230512169437.
Another Giuga number (but possibly not the 13th) is 4200017949707747062038711509670656632404195753751630609228764416142557211582098432545190323474818 = 2 * 3 * 11 * 23 * 31 * 47059 * 2217342227 * 1729101023519 * 8491659218261819498490029296021 * 58254480569119734123541298976556403.

Crossrefs

Cf. A007850, A216823, A216824, A236433.

Sequence in context: A361503 A265668 A273087 * A138182 A167835 A102044

Adjacent sequences: A236431 A236432 A236433 * A236435 A236436 A236437

Keyword

nonn,tabf,hard

Author

Jonathan Sondow, Jan 25 2014

Status

approved