private static bool IsLowPrime(BigInteger i)
{
var lowPrimes = new BigInteger[] { 3u, 5u, 7u, 11u, 13u, 17u, 19u, 23u, 29u, 31u, 37u, 41u, 43u, 47u, 53u, 59u, 61u, 67u, 71u, 73u, 79u, 83u, 89u, 97u, 101u, 103u, 107u, 109u, 113u, 127u, 131u, 137u, 139u, 149u, 151u, 157u, 163u, 167u, 173u, 179u, 181u, 191u, 193u, 197u, 199u, 211u, 223u, 227u, 229u, 233u, 239u, 241u, 251u, 257u, 263u, 269u, 271u, 277u, 281u, 283u, 293u, 307u, 311u, 313u, 317u, 331u, 337u, 347u, 349u, 353u, 359u, 367u, 373u, 379u, 383u, 389u, 397u, 401u, 409u, 419u, 421u, 431u, 433u, 439u, 443u, 449u, 457u, 461u, 463u, 467u, 479u, 487u, 491u, 499u, 503u, 509u, 521u, 523u, 541u, 547u, 557u, 563u, 569u, 571u, 577u, 587u, 593u, 599u, 601u, 607u, 613u, 617u, 619u, 631u, 641u, 643u, 647u, 653u, 659u, 661u, 673u, 677u, 683u, 691u, 701u, 709u, 719u, 727u, 733u, 739u, 743u, 751u, 757u, 761u, 769u, 773u, 787u, 797u, 809u, 811u, 821u, 823u, 827u, 829u, 839u, 853u, 857u, 859u, 863u, 877u, 881u, 883u, 887u, 907u, 911u, 919u, 929u, 937u, 941u, 947u, 953u, 967u, 971u, 977u, 983u, 991u, 997 };
return(lowPrimes.Contains(i));
}
