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 A281878 #16 Jun 26 2019 00:39:19 %S A281878 0,2,1,4,3,8,5,6,7,412,9,20,21,16,111,112,121,120,29,212,11,12,125, %T A281878 234,149,230,203,216,143,258,305,252,167,432,161,116,123,214,165,202, %U A281878 129,238,303,298,321,250,207,434,323,294,307,612,325,232,141,256,505,292,147,416,503,438,349,474,347,414,329,492,385,676,525,656,507 %N A281878 The sum of two successive terms is prime and the sum of two successive digits is also prime. %C A281878 The sequence is started with a(1)=0 and always extended with the smallest integer not yet present in the sequence and not leading to a contradiction. %H A281878 Jean-Marc Falcoz, <a href="/A281878/b281878.txt">Table of n, a(n) for n = 1..10001</a> %e A281878 Prime sum of successive terms: %e A281878 0+2 is prime; 2+1 is prime; 1+4 is prime; ... 6+7 is prime; 7+412 is prime; 412+9 is prime; etc. %e A281878 Prime sum of successive digits: 0+2 is prime; 2+1 is prime; 1+4 is prime; ... 6+7 is prime; 7+4 is prime; 4+1 is prime; 1+2 is prime; etc. %Y A281878 Cf. A217555. %K A281878 nonn,base %O A281878 1,2 %A A281878 _Eric Angelini_ and _Jean-Marc Falcoz_, Feb 01 2017