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 A181346 #18 Oct 14 2018 12:36:51 %S A181346 1,2,0,2,2,4,2,4,2,4,6,2,6,4,2,4,6,6,2,6,4,2,6,4,6,8,4,2,4,2,4,14,4,6, %T A181346 2,10,2,6,6,4,6,6,2,10,2,4,2,12,12,4,2,4,6,2,10,6,6,6,2,6,4,2,10,14,4, %U A181346 2,4,14,6,10,2,4,6,8,6,6,4,6,8,4,8,10,2,10,2,6,4,6,8,4,2,4,12,8,4,8,4,6,12 %N A181346 Absolute difference between (sum of previous terms) and prime(n) with a(0) = 1 and a(1) = 2. %C A181346 Essentially a duplicate of A001223: equals A001223 with terms 2,0 inserted after the initial one. %p A181346 A181346 := proc(n) option remember; if n <= 1 then return n+1 ; end if; add( procname(i),i=0..n-1)-ithprime(n) ; abs(%) ;end proc: %p A181346 seq(A181346(n),n=0..100) ; # _R. J. Mathar_, Oct 15 2010 %Y A181346 Cf. A001223. %Y A181346 Cf. A054541. - _Georg Fischer_, Oct 12 2018 %K A181346 nonn,less %O A181346 0,2 %A A181346 _Giovanni Teofilatto_, Oct 14 2010 %E A181346 Offset and indexing corrected by _R. J. Mathar_, Oct 15 2010