A068883 Smallest n-digit triangular numbers with property that digits alternate in parity, or 0 if no such number exists.
1, 10, 105, 1830, 10585, 107416, 1038961, 10109256, 101410161, 1014503490, 10143650961, 101072103210, 1012143638925, 10101274165450, 101014143472945, 1010363290981278, 10101078125834905, 101012169252147076, 1010125816103490141
Offset: 1
Examples
a(4) = 1830 is a term as 1, 8, 3 and 0 have odd and even parity alternately.
Links
- Sean A. Irvine, Table of n, a(n) for n = 1..50
Extensions
a(7)-a(18) from Donovan Johnson, Mar 14 2010
a(19) from Donovan Johnson, Mar 11 2011