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2020-07-08, 18:05   #872
sweety439

Nov 2016

2·7·132 Posts

Quote:
 Originally Posted by sweety439 There are other k's excluded from the Riesel/Sierpinski problems (Riesel is still much more such k's) * R30 k=1369: for even n let n=2*q; factors to: (37*30^q - 1) * (37*30^q + 1) odd n: covering set 7, 13, 19 * R88 k=400: for even n let n=2*q; factors to: (20*88^q - 1) * (20*88^q + 1) odd n: covering set 3, 7, 13 * R95 k=324: for even n let n=2*q; factors to: (18*95^q - 1) * (18*95^q + 1) odd n: covering set 7, 13, 229 * S55 k=2500: odd n: factor of 7 n = = 2 mod 4: factor of 17 n = = 0 mod 4: let n=4q and let m=5*55^q; factors to: (2*m^2 + 2m + 1) * (2*m^2 - 2m + 1) * S200 k=16: odd n: factor of 3 n = = 0 mod 4: factor of 17 n = = 2 mod 4: let n = 4*q - 2 and let m = 20^q*10^(q-1); factors to: (2*m^2 + 2m + 1) * (2*m^2 - 2m + 1) * S225 k=114244: for even n let k=4*q^4 and let m=q*15^(n/2); factors to: (2*m^2 + 2m + 1) * (2*m^2 - 2m + 1) odd n: factor of 113 * R10 k=343: n = = 1 mod 3: factor of 3 n = = 2 mod 3: factor of 37 n = = 0 mod 3: let n=3q and let m=7*10^q; factors to: (m - 1) * (m^2 + m + 1) * R957 k=64: n = = 1 mod 3: factor of 73 n = = 2 mod 3: factor of 19 n = = 0 mod 3: let n=3q and let m=4*957^q; factors to: (m - 1) * (m^2 + m + 1) * S63 k=3511808: n = = 1 mod 3: factor of 37 n = = 2 mod 3: factor of 109 n = = 0 mod 3: let n=3q and let m=152*63^q; factors to: (m + 1) * (m^2 - m + 1) * S63 k=27000000: n = = 1 mod 3: factor of 37 n = = 2 mod 3: factor of 109 n = = 0 mod 3: let n=3q and let m=300*63^q; factors to: (m + 1) * (m^2 - m + 1) * R936 k=64: n = = 0 mod 2: let n = 2q; factors to: (8*936^q - 1) * (8*936^q + 1) n = = 0 mod 3: let n=3q; factors to: (4*936^q - 1) * [16*936^(2q) + 4*936^q + 1] n = = 1 mod 6: factor of 37 n = = 5 mod 6: factor of 109
Of course,

* In the Riesel case if k and b are both r-th powers for an r>1

* In the Sierpinski case if k and b are both r-th powers for an odd r>1

* In the Sierpinski case if k is of the form 4*m^4, and b is 4th power

Then this k proven composite by full algebraic factors