Landau 4 census through n = 10^7

Replay from this directory:

./run_all.sh

That rebuilds the C residue sieve, writes prime_n.txt and p2_omega2.txt, checks that they extend the committed N=10^6 lists, then verifies the lists twice: a C trial-plus-Pollard pass (different algorithm from the residue sieve) and ../verify.py (Miller–Rabin rescan, multiply-back, and an independent Python factorization). gcc -O3 and Python 3 are enough; this machine has no make.

The sieve refuses a run whose leftover arrays would exceed about 1.8 GiB. At N=10^7 the resident set is about 56 MB.

../sieve_n2p1.py --dir . --n-max 10000000 is the same residue algorithm in Python and is slower. Keep it as the readable reference.

This is a finite classification, not a proof that there are infinitely many primes n^2+1.