A121760/1: two (interesting?) sequences

[Dean Hickerson]

Mostly to Neil Sloane:

> I almost never disagree with Dean, but there IS a difference here:
>
> primes with last digit 3    is "base"
> primes == 1 mod 4           is not
>
> in other words, if the def. explicitly mentions "digit", then is
> probably base

I'm not sure we actually disagree here.  But I think that if a sequence's
definition mentions digits when it could be described in terms of a simple
congruence, then the definition should be changed so the "base" keyword
isn't needed.

I see that you removed "base" from A061237-A061242 (primes congruent to
k (mod 9) for 6 values of k).  It should probably also be removed from:

    A023105, Number of distinct quadratic residues mod 2^n. 	
    A039301, Number of distinct quadratic residues mod 4^n. 	
    A039302, Number of distinct quadratic residues mod 5^n. 	
    A039303, Number of distinct quadratic residues mod 6^n. 	
    A039304, Number of distinct quadratic residues mod 7^n. 	
    A039305, Number of distinct quadratic residues mod 8^n. 
    A039306, Number of distinct quadratic residues mod 9^n. 	
    A000993, Number of distinct quadratic residues mod 10^n = number of
             distinct n-digit endings of base 10 squares. 

Maybe also:

    A008975	Pascal's triangle mod 10
    A074822	Primes p(n) such that p(n) + 4 = p(n+1) and p(n) == 9 (Mod 10)
    A087355	n^10 mod 10^n

Dean Hickerson
dean at math.ucdavis.edu