Primes sorted by relation of largest divisors of p+-1

[Alonso Del Arte]

Speaking for myself, you may bother me with problems of this sort, so
long as you separate the numbers with commas ("," or ", ") instead of
just spaces. ;)

After some mass replaces in Notepad, I entered your lists of primes
such that the number of divisors of p-1 is greater than the
number of divisors of p+1 and the other one into Mathematica as
HugoList1 and 2. Then, I executed

Select[Prime[Range[2, 140]], Length[Divisors[# - 1]] >
Length[Divisors[# + 1]] &]

and a similar one with only a change of comparison operator (based on
Wouter's code). Then

SameQ[%, HugoList1]

and a similar one. For both Mathematica replied True.

Alonso

On Sat, 19 Feb 2005 21:42:27 +0100, Hugo Pfoertner <all at abouthugo.de> wrote:
> Thanks to Wouter, Vladeta and Cino.
>
> May I bother you with another similar problem. Not yet submitted, more
> manual actions, so higher probability of being wrong:
>
> Primes p such that the number of divisors of p-1 is less than the number
> of divisors of p+1.
>
> 3 5 11 17 23 29 47 53 59 71 79 83 89 107 131 139 149 167 173 179 191 197
> 223 227 233 239 251 263 269 293 311 317 347 359 367 383 389 419 431 439
> 443 449 461 467 479 499 503 509 557 563 569 587 593 599 607 619 643 647
> 653 659 683 719 727 743 773 797 809
>
> a(1)=3 because d(2)=2 < d(4)=3
>
> Primes p such that the number of divisors of p-1 is greater than the
> number of divisors of p+1.
>
> 13 31 37 43 61 67 73 97 101 109 113 127 151 157 163 181 193 211 229 241
> 257 271 277 281 283 313 331 337 353 373 379 397 401 409 421 433 457 463
> 487 521 523 541 547 571 577 601 613 617 631 641 661 673 677 691 701 709
> 733 751 757 761 769 787
>
> a(1)=13 because d(12)=6 > d(14)=4.
>
> BTW, equal number of divisors is
> http://www.research.att.com/projects/OEIS?Anum=A067889
>
> Hugo
>