Problems & Puzzles: Puzzles

Puzzle 981. Redo Puzzle 957 for titanic prime solutions Puzzle 957 received all the solutions from Paul Cleary. None of these were titanic prime solutions. The larger solutions were for the form b), with 753 digits. Here we ask to redo Puzzle 957 but sending only titanic (more than 999 digits) prime solutions. Q. Send your largest titanic solutions for all of the four forms.

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Contributions came from Metin Sariyar, Fausto Morales, Simon Cavegn, Adam Stinchcombe.

All of these came during the week 30 Nov-7 Dic, 2019.

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Metin wrote:

a) -(1^2)*3+4*56^789          1380 digit prime
 

b) -12*3*4+5*67^890           1626 digit prime

c) (9^(8*7*6*5))*4-(3*2+1)   1604 digits prime.

d)  9-8+(76^(5^4)+32)*10    1177 digit prime

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Fausto wrote:

Type a: 1 * 2 ^ ( 3 + 4 + 56 * 78 ) + 9, 1318 digits, prime

Type c: 9 + ( 8 ^ ( 7 * 6 * ( 5 ^ 4 ) / ( - 3 + 21 ) ) ), 1318 digits, prime

Please notice that both primes are the same integer just computed with two different expressions... (Wow!, CR)

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Simon wrote:

Type A) 10930 digits: 1+(2+3)^((4+(5^6))+7)+8+9

Type C) 7941 digits: ((9^8)*(7^6))^(5^4)+3-2+1

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Adam wrote:

I didn’t hit (yet) your titanic (1000+ digits) of puzzle 981 but

 

(1+23+4)^567-89 is an 820 digit number that passes Maple’s isprime test.

 

Also,  1*2+(34^56+7-8)^9 is a 771 digit number that passes isprime.

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