A236381
Smallest value of x such that x^2 + y^2 = P, where P is the product of the first n primes of the form 4k + 1, and 0 < x < y.
Original entry on oeis.org
1, 1, 4, 2, 64, 59, 1342, 1076, 4268, 10739, 64387, 818998, 3226976, 26444853, 53155423, 1175849126, 13396689992, 2368807981, 907313696551, 483703442648, 2835669288809, 98713800566163, 24423236756993, 6054940274199961, 17628259859562384, 128658404383205917, 3865377837569367511
Offset: 1
a(3) = 4 because the solutions to x^2 + y^2 = 5*13*17 are (x,y) = (23,24), (9,32), (4,33), (12,31) of which the smallest value of x is 4.
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prd(n) = my(q=3, t=1); for(k=1, n, until(q%4==1, q=nextprime(q+1)); t*=q); t; \\ A006278
a(n) = {my(t=prd(n), q=0); until(issquare(t-q^2), q++); q; } \\ Michel Marcus, Mar 05 2021
A236421
Largest value of x such that x^2 + y^2 = P, where P is the product of the first n primes of the form 4k + 1, and 0 < x < y.
Original entry on oeis.org
1, 4, 23, 122, 743, 4851, 35579, 279644, 2390953, 22510892, 222505867, 2236298893, 23344760669, 248205367341, 2905133255201, 35462464074278, 444339941124303, 5844308003978966, 78628682982091847, 1092345114491353169, 15331801966256295943
Offset: 1
a(3) = 23 because the solutions to x^2 + y^2 = 5*13*17 are (x,y) = (23,24), (9,32), (4,33), (12,31) of which the largest value of x is 23.
A236422
Values of y corresponding to the largest value of x such that x^2 + y^2 = P, where P is the product of the first n primes of the form 4k + 1, and 0 < x < y.
Original entry on oeis.org
2, 7, 24, 131, 796, 5008, 36202, 281003, 2399224, 22679301, 222569004, 2236648234, 23354177528, 248211165052, 2905273285888, 35462586540039, 444348395841976, 5844562089950893, 78628980833594936, 1092348171981581852, 15331829536310136066
Offset: 1
a(3) = 24 because the solutions to x^2 + y^2 = 5*13*17 are (x,y) = (23,24), (9,32), (4,33), (12,31) and the value of y corresponding to the largest value of x is 24.
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