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 A080465 #21 Nov 10 2019 01:32:10 %S A080465 1,0,1,2,3,4,5,6,7,8,2,1,0,1,2,3,4,5,6,7,3,2,1,0,1,2,3,4,5,6,4,3,2,1, %T A080465 0,1,2,3,4,5,5,4,3,2,1,0,1,2,3,4,6,5,4,3,2,1,0,1,2,3,7,6,5,4,3,2,1,0, %U A080465 1,2,8,7,6,5,4,3,2,1,0,1,9,8,7,6,5,4,3,2,1,0,10,11,12,13,14,15,16,17,18,19,9 %N A080465 Absolute difference between the two numbers formed by alternate digits of n. %C A080465 Differs from A040115 first at a(110) = 9. - _R. J. Mathar_, Sep 19 2008 %H A080465 T. D. Noe, <a href="/A080465/b080465.txt">Table of n, a(n) for n=10..10000</a> %e A080465 a(132546) = |124 - 356| = 232. %o A080465 (PARI) A080465(n)=abs(vector(#n=digits(n),j,(-1)^j*10^((#n-j)\2))*n~) \\ _M. F. Hasler_, Jan 10 2016 %Y A080465 Cf. A080463, A080464, A267086. %Y A080465 See also A040997. %K A080465 base,easy,nonn,look %O A080465 10,4 %A A080465 _Amarnath Murthy_, Mar 02 2003 %E A080465 More terms from _Ray Chandler_, Oct 11 2003