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 A295746 #65 Mar 02 2019 04:22:18 %S A295746 1,0,2,-2,-4,4,10,-10,8,-8,6,16,-12,-16,12,-14,-20,28,-28,-6,22,14,20, %T A295746 26,-26,-22,-24,24,-18,18,32,-32,-30,40,-40,30,-38,-34,46,38,50,-46, %U A295746 34,68,-64,-44,58,-58,-48,-50,48,52,-54,44,-52,36,-42,56 %N A295746 Distinct second differences in the sequence of primes in order of appearance. %C A295746 A036263 excluding repeated terms. - _Iain Fox_, Nov 30 2017 %H A295746 Robert G. Wilson v, <a href="/A295746/b295746.txt">Table of n, a(n) for n = 1..358</a> (first 97 terms from Edward Bernstein) %e A295746 From _Jon E. Schoenfield_, Jan 15 2018: (Start) %e A295746 The first several primes and their 1st and 2nd differences are as follows: %e A295746 . %e A295746 k prime(k) 1st difference 2nd difference %e A295746 -- -------- -------------- ------------------- %e A295746 1 2 %e A295746 3 - 2 = 1 %e A295746 2 3 2 - 1 = 1 (new) %e A295746 5 - 3 = 2 %e A295746 3 5 2 - 2 = 0 (new) %e A295746 7 - 5 = 2 %e A295746 4 7 4 - 2 = 2 (new) %e A295746 11 - 7 = 4 %e A295746 5 11 2 - 4 = -2 (new) %e A295746 13 - 11 = 2 %e A295746 6 13 4 - 2 = 2 (repeat) %e A295746 17 - 13 = 4 %e A295746 7 17 2 - 4 = -2 (repeat) %e A295746 19 - 17 = 2 %e A295746 8 19 4 - 2 = 2 (repeat) %e A295746 23 - 19 = 4 %e A295746 9 23 6 - 4 = 2 (repeat) %e A295746 29 - 23 = 6 %e A295746 10 29 2 - 6 = -4 (new) %e A295746 31 - 29 = 2 %e A295746 11 31 %e A295746 . %e A295746 and the 2nd differences that are not repeats of 2nd differences encountered earlier are, in order of appearance, 1, 0, 2, -2, -4, ..., i.e., the terms of this sequence. (End) %p A295746 P:= select(isprime, [2,seq(i,i=3..10^6,2)]): %p A295746 DP:= P[2..-1]-P[1..-2]: %p A295746 DDP:= DP[2..-1]-DP[1..-2]: %p A295746 ListTools:-MakeUnique(DDP); # _Robert Israel_, Jan 15 2018 %t A295746 DeleteDuplicates@ Differences[Prime@ Range[10^4], 2] (* _Michael De Vlieger_, Dec 09 2017 *) %o A295746 (PARI) first(n) = { my(res = vector(n), i=3, j=3); res[1]=1; res[2]=0; while(i<=n, my(d=prime(j+2)+prime(j)-2*prime(j+1)); if(!setsearch(Set(res), d), res[i]=d; i++); j++); res; } \\ _Iain Fox_, Nov 30 2017 %Y A295746 Cf. A036263. A295973 are the primes associated with the new second differences. %K A295746 sign %O A295746 1,3 %A A295746 _Edward Bernstein_, Nov 29 2017