[SOLVED] sequence equation

I need help trying to get the correct equation i have been to college but its been a long time since i droped out for medical reasons so i've lost abit of the algebra methods and this one is the very difficult because i need it for personal project so here goes it and i'll try my best to explain it :

there are 8 diffrent lettes a, b, c, d, e, f, g, h

1 : any one of them can come at any random sequence

the sequence goes to 1 billion billion 1 followed by 18 "0's"

2 : then this sequence is set to equal a if it ends at a, b if it ends at b, c if it ends at c, d if it ends at d, e if it ends at e, f if it ends at f, g if it ends at g, h if it ends at h, some time it doesn't reach that ie below 1 billion billion

3 : this process is repeated 1 billion billion times so what is the sequence,say some times it doesn't reach that number is i.e below 1 billion billion etc

4: i.e i want a formula that puts these together

can be eight or ten formula's in one or what ever

i.e first getting the letters sequence is x=a+b+c+d+e+f+g+h ie x is a or b or c or d or e or f or g

giving example a is sequence 1, b is 2, c is 3, d is 4, e is 5, f is 6, g is 7, h is 8 and so on

so this keeps on going till the figure reaches 1 billion billion as a set figure for your benefit but say if i want the number to be infinite ie 19870694763655^109674653094 or so on what would that formula be

can you please give me the whole formula generalized

1: y=(8^n)^q+1 etc or 2: y=(8^(8!))^p^n

1:y= the infinte number, n=the number of the sequence,q is the number of times the process is repeated, 8 is number of different possible letters. 2: y is the infinite number, 8 is the different number of letter's,p is the number of sequence, n is the number of times the process is repeated

is the equation y=(8^n)^p

where y= the final letter,8= the different lots of letters i.e eight different letters a, b, c, d, e, f, g & h, n= number of letters in one sequence and p= the number of times it is repeated

i would be very greatful if you could reply ASAP thanks please let me know if this is correct thanks