This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A058296 #16 Aug 11 2025 13:24:08
%S A058296 2,4,9,15,21,30,39,45,56,64,72,81,93,102,108,120,134,144,154,165,176,
%T A058296 186,195,205,225,231,240,254,266,274,282,300,312,324,342,351,363,376,
%U A058296 386,399,414,426,436,446,459,465,483,495,506,522,544,560,570,582,596
%N A058296 Average of consecutive primes.
%C A058296 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
%H A058296 Harry J. Smith, <a href="/A058296/b058296.txt">Table of n, a(n) for n = 1..20000</a>
%H A058296 Donald Mills, <a href="https://web.archive.org/web/20040216045248/http://www.math.siu.edu/mills/interesting_seqs.pdf">Some Interesting Sequences</a>.
%F A058296 a(1)=2, a(n) = (prime(2n-2) + prime(2n-1))/2 for n>1, where prime(i) is the i-th prime.
%p A058296 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);
%t A058296 Join[{2},Mean/@Partition[Prime[Range[2,121]],2]] (* _Harvey P. Dale_, Apr 09 2018 *)
%o A058296 (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
%Y A058296 A bisection of A024675.
%Y A058296 Cf. A000040, A079424.
%K A058296 easy,nonn
%O A058296 1,1
%A A058296 Donald Mills (dmills(AT)math.siu.edu), Feb 16 2003