A146764 Primes not in A075255.

13, 61, 73, 109, 151, 181, 229, 241, 257, 293, 307, 313, 349, 353, 373, 397, 409, 487, 509, 557, 571, 577, 601, 613, 643, 653, 661, 709, 727, 733, 739, 751, 761, 773, 811, 823, 937, 941, 977

Offset

1,1

Comments

It has been asked whether A146071 contains all primes. The answer is no: since A075255(n) > n/2-2 for nonprime n, any prime p that did not appear until the rank 2(p+2) is not in A075255. This is a sufficient condition for not being in A146071, but unless proved otherwise, there may be primes in A075255, i.e., not listed here, which nevertheless do not appear in A146071.

Links

Table of n, a(n) for n=1..39.

Prog

(PARI) A146764( END=999 )=local( n=1, t=0, k); forprime( p=1, END, while( n<2*(p+2), isprime( k=A075255(n++)) || next; t=bitor(1<<primepi(k), t)); bittest(t, primepi(p)) || print1(p", "))

Crossrefs

Cf. A075255, A146071, A145834.

Sequence in context: A228558 A316550 A244923 * A336794 A145474 A359666

Adjacent sequences: A146761 A146762 A146763 * A146765 A146766 A146767

Keyword

easy,nonn

Author

M. F. Hasler, Nov 04 2008

Status

approved