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 A247380 #14 Sep 15 2014 15:54:24 %S A247380 3,7,11,23,21,37,31,51,77,49,97,85,67,99,137,149,93,169,143,111,199, %T A247380 167,221,281,197,153,211,163,225,533,251,323,203,479,219,367,379,315, %U A247380 401,413,261,601,277,369,287,751,775,415,325,429,539,343,771,575,587,599 %N A247380 First differences of A117495. %H A247380 Alois P. Heinz, <a href="/A247380/b247380.txt">Table of n, a(n) for n = 1..10000</a> %F A247380 a(n) = A117495(n+1) - A117495(n). %p A247380 with(numtheory): %p A247380 a:= n-> ithprime(n+1)*n-ithprime(n)*(n-1): %p A247380 seq(a(n), n=1..60); # _Alois P. Heinz_, Sep 15 2014 %o A247380 (PARI) a(n)=my(p=prime(n++)); p+n*(nextprime(p+1)-p) \\ _Charles R Greathouse IV_, Sep 15 2014 %Y A247380 Cf. A000040, A117495. %K A247380 easy,nonn %O A247380 1,1 %A A247380 _Odimar Fabeny_, Sep 15 2014 %E A247380 More terms from _Alois P. Heinz_, Sep 15 2014