This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A258934 Half the difference between the 2n-th prime and the n-th prime, starting from n=2. 0
 2, 4, 6, 9, 12, 13, 17, 19, 21, 24, 26, 30, 32, 33, 39, 40, 45, 48, 51, 54, 57, 58, 67, 66, 69, 74, 78, 81, 84, 83, 90, 90, 99, 100, 104, 108, 110, 115, 118, 121, 126, 126, 132, 133, 140, 140, 140, 147, 156, 162, 165, 168, 171, 172, 175, 175, 185, 185, 189 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS The differences between odd prime numbers are always even, so a(n) is well defined for n>=2. LINKS FORMULA a(n) = ( prime(2*n) - prime(n) ) / 2. a(n) = A072473(n)/2. MATHEMATICA Table[(Prime[2 k] - Prime[k])/2, {k, 2, 60}] PROG (Sage) [(nth_prime(2*n)-nth_prime(n))/2 for n in (2..60)] # Bruno Berselli, Jun 15 2015 (MAGMA) [(NthPrime(2*n)-NthPrime(n))/2: n in [2..60]]; // Bruno Berselli, Jun 15 2015 CROSSREFS Cf. A072473, A072715, A087461. Sequence in context: A220768 A077220 A128716 * A225600 A183422 A025057 Adjacent sequences:  A258931 A258932 A258933 * A258935 A258936 A258937 KEYWORD nonn,easy AUTHOR Federico Provvedi, Jun 15 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 17 22:17 EDT 2019. Contains 324200 sequences. (Running on oeis4.)