A101947 A101909 sorted and duplicates removed.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73

Offset: 1

Author

Cino Hilliard, Jan 28 2005

Keywords

• easy
• nonn

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A101909, A101983-A101985.

Programs

PARI

bet2n4n(n) = { local(c,c1,x,y); a=vector(5001); for(x=1,n, c=0; forprime(y=2*x+1,4*x-1, c++; ); a[x] = c; ); b=vecsort(a); for(x=1,5000, if(b[x]>0, if(b[x]<>b[x+1],print1(b[x]",") ) ); ) }

PARI

s=0;v=vectorsmall(10^6,n,s+=isprime(4*n-1)+isprime(4*n-3)-isprime(2*n-1));v=vecsort(v,,8);vecextract(v,Str("1..",#v\2)) \\ Charles R Greathouse IV, Mar 12 2012