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

1,2

Links

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

Example

a(4) = 1830 is a term as 1, 8, 3 and 0 have odd and even parity alternately.

Crossrefs

Cf. A068876, A030152, A068882, A068884.

Sequence in context: A240681 A113348 A193274 * A087599 A337826 A226360

Adjacent sequences: A068880 A068881 A068882 * A068884 A068885 A068886

Keyword

base,nonn

Author

Amarnath Murthy, Mar 19 2002

Extensions

a(7)-a(18) from Donovan Johnson, Mar 14 2010

a(19) from Donovan Johnson, Mar 11 2011

Status

approved