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 A161625 #5 Mar 31 2012 08:19:37 %S A161625 3,6,15,28,1,6,28,45,6,45,1,28,1,6,28,6,45,1,28,1,6,45,6,45,28,1,6,28, %T A161625 45,6,28,1,28,45,45,1,28,6,28,6,45,1,1,6,28,45,1,6,28,45,6,45,1,1,28, %U A161625 6,45,1,28,1,6,6,28,1,6,28,1,28,28,45,6,45,28,6,45,6,45,28,1,45 %N A161625 Sum of all numbers from 1 up to the final digit of prime(n). %F A161625 a(n)= A000217(A007652(n)). - _R. J. Mathar_, Jun 16 2009 %e A161625 a(1)=3=1+2. a(2)=6=1+2+3. a(3)=15=1+2+3+4+5. a(4)=28=1+2+3+4+5+6+7. a(5)=1=1. a(6)=3=1+2. %p A161625 A007652 := proc(n) ithprime(n) mod 10; end: A000217 := proc(n) n*(n+1)/2 ; end: %p A161625 A161625 := proc(n) A000217(A007652(n)) ; end: seq(A161625(n),n=1..80) ; # _R. J. Mathar_, Jun 16 2009 %Y A161625 Cf. A000027, A000040, A161570. %K A161625 nonn,base,less %O A161625 1,1 %A A161625 _Juri-Stepan Gerasimov_, Jun 15 2009 %E A161625 Definition reworded and a 16 split in 1,6 by _R. J. Mathar_, Jun 16 2009