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

6, 78, 903, 9870, 96141, 941878, 9850141, 98947278, 985036305, 9892547470, 98585094741, 989436909450, 9898947258903, 98969892923278, 989872901298945, 9898987276765450, 98985850965876105, 989898183850729896, 9898969072503098503

Offset

1,1

Links

Sean A. Irvine, Table of n, a(n) for n = 1..50

Example

a(4) = 9870 is a term as 9, 8, 7 and 0 have odd and even parity alternately.

Crossrefs

Cf. A068876, A030152, A068882, A068883.

Sequence in context: A370714 A145360 A183405 * A186663 A069670 A074112

Adjacent sequences: A068881 A068882 A068883 * A068885 A068886 A068887

Keyword

base,nonn

Author

Amarnath Murthy, Mar 19 2002

Extensions

a(6)-a(19) from Donovan Johnson, Mar 11 2011

Status

approved