A068855 -id:A068855

Search: a068855 -id:a068855

Displaying 1-2 of 2 results found.

page 1

A068865

a(1) = 1; a(n) is the smallest triangular number not already in the sequence which differs from a(n-1) at every digit.

+10
2

1, 3, 6, 10, 21, 15, 28, 36, 45, 66, 55, 78, 91, 105, 210, 136, 253, 120, 231, 153, 276, 190, 325, 171, 300, 435, 351, 406, 378, 465, 528, 496, 561, 630, 595, 666, 703, 820, 741, 903, 780, 861, 946, 1035, 990, 1081, 2145, 1326, 2080, 1128, 2016, 1225, 2346

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

136 follows 210 as the smallest triangular number not included earlier and differing at every digit position with 210.

CROSSREFS

Cf. A000217, A068855.

KEYWORD

nonn,base

AUTHOR

Amarnath Murthy, Mar 13 2002

EXTENSIONS

Corrected and extended by Sascha Kurz, Feb 02 2003

STATUS

approved

A068866

Triangular numbers k*(k+1)/2 such that A068865(k) = k*(k+1)/2.

+10
0

1, 3, 6, 10, 28, 36, 45, 78, 91, 105, 136, 406, 465, 561, 666, 703, 946, 1081, 3240, 6555, 7260, 9045, 32640, 46971, 47586, 48828, 51360, 70876, 72390, 94395, 319600, 719400, 903840, 914628, 4862521, 5092836, 5112003, 5131206, 6898755, 7108335, 9122856

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..41.

CROSSREFS

Cf. A068855, A068865.