[seqfan] A057471

[юрий герасимов]

Dear Segfans, 
If
A057471   =    numbers n such that (11*13^n - 1)/2 is prime   =  0, 1, 2, 5, 9, 11, 21, 42, 46, 61, 69, 70, 78, 99, 103, 361, 1034, 1291, 1570, 1838, ...
then 
A______?  =   numbers n such that (13*15^n - 1)/(3 + (-1)^n) is prime  =  0, 3, 4, 6, 7, 8,...
or
A______?  =   numbers n such that (5*7^n - 1)/(3 - (-1)^n) is prime  =  1, 2, 3, 4, 5, 7, 16,..
or
A______?  =  numbers n such that (7*9^n - 1)/2 is prime  =  0, 1, 2, 3, 4, 8, 9, 14,...

Help calculat the number of sequences by computer, kotortse may be of common interest.

Regards,
Juri-Stepan Gerasimov,