A134196 -id:A134196 - cp's OEIS frontend

A133261 Union of A134196 and A134197 : A126990 with duplicates removed.

3, 7, 13, 19, 23, 31, 37, 43, 47, 53, 61, 67, 73, 83, 89, 97, 103, 109, 113, 131, 139, 151, 157, 167, 173, 181, 193, 199, 211, 223, 229, 233, 241, 251, 257, 263, 271, 277, 283, 293, 307, 313, 317, 337, 349, 353, 359, 367, 373, 383, 389, 401, 409, 421, 433, 443

Offset: 1

Artur Jasinski, Oct 15 2007

nonn

Cf. A134196, A134197, A126990.

<< NumberTheory`NumberTheoryFunctions` a = {}; Do[AppendTo[a, PreviousPrime[Sqrt[(Prime[ x - 1])*(Prime[x + 1])]]], {x, 2, 300}]; Union[a]

A134197 Primes that occur in A126990 twice.

Original entry on oeis.org

3, 7, 13, 23, 31, 47, 61, 73, 89, 103, 113, 131, 139, 151, 167, 181, 193, 199, 233, 241, 271, 293, 317, 337, 359, 389, 409, 421, 433, 449, 467, 491, 509, 523, 547, 577, 601, 619, 647, 661, 691, 709, 743, 761, 773, 797, 811, 823, 839, 863, 887, 919, 941, 953

Offset: 1

Artur Jasinski, Oct 13 2007

nonn

It seems, as tested up to prime(100000), that triplicates of primes do not occur in A126990, so this sequence stays the same if defined as either "... in A126990 exactly twice" or "... in A126990 at least twice." - Michel Marcus and R. J. Mathar, Nov 07 2013

Amiram Eldar, Table of n, a(n) for n = 1..10000

Cf. A126990, A134196.

lista(nn) = {last = A126990(1); for (n=2, nn, new = A126990(n); if (new == last, print1(new, ", ")); last = new;);} \\ Michel Marcus, Nov 07 2013

More terms from Michel Marcus, Nov 07 2013

A134240 Numbers which occur in A105399 but not in A126990.

Original entry on oeis.org

79, 127, 163, 331, 379, 397, 439, 487, 499, 541, 673, 701, 739, 757, 769, 787, 907, 937, 947, 967, 977, 991, 1009, 1103, 1123, 1163, 1187, 1213, 1249, 1367, 1399, 1523, 1549, 1567, 1579, 1597, 1753, 1801

Offset: 1

Artur Jasinski, Oct 15 2007

nonn

Cf. A105399, A134196, A134197, A126990.

cp's OEIS Frontend

A133261 Union of A134196 and A134197 : A126990 with duplicates removed.

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A134197 Primes that occur in A126990 twice.

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A134240 Numbers which occur in A105399 but not in A126990.

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