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 A173817 #14 Jan 27 2019 03:01:31 %S A173817 1,2,4,5,10,10,13,13,16,20,25,27,28,26,31,33,44,42,47,52,48,54,52,60, %T A173817 64,68,64,67,68,77,108,94,102,95,106,100,103,106,105,106,115,110,127, %U A173817 120,131,122,143,159,149,148,156,149,151,155,165,162,167,174,175 %N A173817 The half of sum of the numbers in the n-th row of Gilbreath's triangle (A036262). %C A173817 Gilbreath's triangle is a triangle of numbers arising from Gilbreath's conjecture: successive absolute differences of primes. %F A173817 a(n) = A173816(n)/2. %p A173817 A036262 := proc(n,k) option remember ; if k = n then ithprime(n) ; else abs(procname(n,k+1)-procname(n-1,k)) ; end if; end proc: A173818 := proc(n) add(A036262(n,k),k=1..n)/2 ; end proc: seq(A173818(n),n=1..90) ; # _R. J. Mathar_, Mar 01 2010 %Y A173817 Cf. A036261, A036262, A173816. %K A173817 nonn %O A173817 1,2 %A A173817 _Juri-Stepan Gerasimov_, Feb 25 2010 %E A173817 a(23) and a(24) corrected and sequence extended by _R. J. Mathar_, Mar 01 2010