A208846 a(n) = A056915(n) mod 76057 mod 13.

2, 7, 11, 10, 5, 9, 6, 3, 4, 0, 1, 12, 8, 8, 6, 10, 9, 6, 7, 10, 3, 6, 2, 9, 8, 1, 2, 2, 2, 8, 0, 5, 5, 2, 7, 11, 5, 2, 11, 0, 10, 8, 2, 7, 4, 10, 2, 0, 5, 12, 8, 11, 6, 7, 7, 11, 0, 5, 1, 12, 6, 4, 6, 7, 8, 1, 12, 0, 7, 2, 9

Offset: 1

Author

Washington Bomfim, Mar 02 2012

Keywords

• nonn

Comments

A056915(n) mod 76057 mod 13 is a bijection from the set of the first 13 terms of A056915 to {0,1,2,3,4,5,6,7,8,9,10,11,12}.

One of the tests for primality described in the first reference when tests x and x is prime, searches a table T composed by the first 13 entries of A056915 to see if x is a strong pseudoprime to bases 2,3 and 5. A fast way to do that is to compute i = x mod 76057 mod 13, and compare x with T[i]. If x is not equal to T[i], x is prime.

Terms computed using table by Charles R Greathouse IV. See A056915.

Links

• Washington Bomfim, A method to find bijections from a set of n integers to {0,1, ... ,n-1}
• C. Pomerance, J. L. Selfridge, and S. S. Wagstaff, Jr., The pseudoprimes to 25*10^9, Mathematics of Computation, 35, 1980, pp. 1003-1026.

Crossrefs

Cf. A055775.