A074899 - OEIS

A074899

Triangular numbers written backwards and sorted, duplicates removed.

1, 3, 6, 12, 19, 21, 28, 36, 51, 54, 55, 63, 66, 82, 87, 91, 99, 102, 109, 132, 147, 153, 165, 168, 171, 208, 252, 307, 309, 351, 352, 379, 381, 417, 423, 451, 501, 505, 507, 523, 534, 564, 577, 582, 591, 594, 595, 604, 613, 627, 631, 645, 649, 654, 666, 672, 694, 753, 766, 771

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..60.

MAPLE

109 is a member because 90100 is a triangular number. - Sean A. Irvine, Feb 01 2025

CROSSREFS

Cf. A004158.

Sequence in context: A327328 A356019 A363463 * A345868 A318872 A267591

Adjacent sequences: A074896 A074897 A074898 * A074900 A074901 A074902

KEYWORD

base,nonn

AUTHOR

Jason Earls, Sep 14 2002

EXTENSIONS

Missing terms inserted by Sean A. Irvine, Feb 01 2025

STATUS

approved