%I #10 Mar 22 2024 16:28:02
%S 6,78,903,9870,96141,941878,9850141,98947278,985036305,9892547470,
%T 98585094741,989436909450,9898947258903,98969892923278,
%U 989872901298945,9898987276765450,98985850965876105,989898183850729896,9898969072503098503
%N Largest ndigit triangular number with property that digits alternate in parity, or 0 if no such number exists.
%H Sean A. Irvine, <a href="/A068884/b068884.txt">Table of n, a(n) for n = 1..50</a>
%e a(4) = 9870 is a term as 9, 8, 7 and 0 have odd and even parity alternately.
%Y Cf. A068876, A030152, A068882, A068883.
%K base,nonn
%O 1,1
%A _Amarnath Murthy_, Mar 19 2002
%E a(6)a(19) from _Donovan Johnson_, Mar 11 2011
