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 A042939 #23 Jun 14 2022 06:23:06
%S A042939 2,3,5,7,0,2,6,8,1,7,2,4,3,1,3,2,4,5,1,6,4,2,5,1,2,0,2,6,8,3,8,3,9,11,
%T A042939 12,5,11,8,12,9,15,8,9,11,15,17,0,3,7,9,4,10,3,4,10,7,13,6,12,7,9,10,
%U A042939 4,1,1,5,1,7,8,10,5,11,10,7,13,8,14,13,3,5,6,1,0,2,8,3,9,8,3,5,9,12,11,6
%N A042939 Absolute values between digits of primes.
%C A042939 a(n) = absolute difference between the first digit of prime(n) and the sum of the other digits of prime(n). [_Harvey P. Dale_, Mar 11 2012]
%H A042939 James Spahlinger, <a href="/A042939/b042939.txt">Table of n, a(n) for n = 1..10000</a>
%F A042939 If decimal expansion of n-th prime is x1 x2 x3......xk then a(n)=|x1-x2-x3.......-xk|
%F A042939 a(n) = A040997(A000040(n)). - _Reinhard Zumkeller_, Oct 10 2012
%t A042939 ddp[n_]:=Module[{idn=IntegerDigits[n]},Abs[First[idn]-Total[Rest[idn]]]]; ddp/@Prime[Range[100]] (* _Harvey P. Dale_, Mar 11 2012 *)
%o A042939 (Haskell)
%o A042939 a042939 = a040997 . a000040
%o A042939 -- _Reinhard Zumkeller_, Oct 10 2012
%Y A042939 Cf. A041000, A040164, A000040.
%Y A042939 Cf. A007605.
%K A042939 base,nonn
%O A042939 1,1
%A A042939 _Felice Russo_