login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A058296
Average of consecutive primes.
5
2, 4, 9, 15, 21, 30, 39, 45, 56, 64, 72, 81, 93, 102, 108, 120, 134, 144, 154, 165, 176, 186, 195, 205, 225, 231, 240, 254, 266, 274, 282, 300, 312, 324, 342, 351, 363, 376, 386, 399, 414, 426, 436, 446, 459, 465, 483, 495, 506, 522, 544, 560, 570, 582, 596
OFFSET
1,1
COMMENTS
2 together with average of odd primes taken two at a time without overlaps, i.e., 2 together with average of (3,5), (7,11), (13,17), etc. - Harvey P. Dale, Apr 09 2018
LINKS
FORMULA
a(1)=2, a(n) = (p(2n-2) + p(2n-1))/2 for n>1, where p(i) is the i-th prime.
MAPLE
with(linalg): v := linalg[vector](100): v[1] := 2: for j from 2 to 100 do v[j] := (ithprime(2*j-2)+ithprime(2*j-1))/2: od: print(v);
MATHEMATICA
Join[{2}, Mean/@Partition[Prime[Range[2, 121]], 2]] (* Harvey P. Dale, Apr 09 2018 *)
PROG
(PARI) { write("b058296.txt", 1, " ", 2); p2=2; for (n=2, 20000, p1=nextprime(p2+1); p2=nextprime(p1+1); a=(p1+p2)/2; write("b058296.txt", n, " ", a); ); } \\ Harry J. Smith, May 30 2009
CROSSREFS
A bisection of A024675. Cf. A079424.
Sequence in context: A042960 A266596 A045975 * A347473 A025217 A119759
KEYWORD
easy,nonn
AUTHOR
Donald Mills (dmills(AT)math.siu.edu), Feb 16 2003
STATUS
approved