A068644 Index of the largest n-digit palindromic triangular number, or 0 if no such number exists.

3, 11, 36, 132, 363, 1287, 3548, 11088, 18906, 111111, 417972, 0, 3707883, 12812392, 37009916, 128127032, 368505751, 1014708805, 3567632391, 11151642876, 36657342048, 104561417190, 417898160427, 1325269593372

Offset

1,1

Links

Table of n, a(n) for n=1..24.

P. De Geest, Exhaustive list of Palindromic Triangulars

Example

a(4) = 132 as 132*133/2 = 8778 is the largest 4-digit palindromic triangular number.
a(12) = 0 as no 12-digit palindromic triangular number exists.

Crossrefs

Cf. A068641, A068642, A068643, A000217, A003098, A008509, A008510, A054263.

Sequence in context: A100068 A260745 A119213 * A286318 A119054 A119090

Adjacent sequences: A068641 A068642 A068643 * A068645 A068646 A068647

Keyword

base,nonn

Author

Amarnath Murthy, Feb 28 2002

Extensions

Edited by Patrick De Geest, Mar 24 2002

Status

approved