A069511 - OEIS

A069511

Numbers in which starting from most significant digit the n-th digit is obtained by adding n to the (n-1)-st digit (the digit to the left of it) and then ignoring the carry. Alternately the n-th digit starting from the most significant digit is the n-th triangular number mod 10.

1, 13, 136, 1360, 13605, 136051, 1360518, 13605186, 136051865, 1360518655, 13605186556, 136051865568, 1360518655681, 13605186556815, 136051865568150, 1360518655681506, 13605186556815063, 136051865568150631, 1360518655681506310, 13605186556815063100

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..20.

FORMULA

a(n) = 10 * a(n-1) + (A000217(n) mod 10) with a(0)=0. - Sean A. Irvine, May 02 2024

CROSSREFS

Cf. A000217.

Sequence in context: A243216 A112225 A391105 * A052262 A065550 A078795

Adjacent sequences: A069508 A069509 A069510 * A069512 A069513 A069514

KEYWORD

nonn,base

AUTHOR

Amarnath Murthy, Mar 30 2002

EXTENSIONS

Offset corrected and more terms from Sean A. Irvine, May 02 2024

STATUS

approved