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A068884 Largest n-digit triangular number with property that digits alternate in parity, or 0 if no such number exists. 2

%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 n-digit 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

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Last modified September 17 23:36 EDT 2024. Contains 375991 sequences. (Running on oeis4.)