A032644 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A032644

Numbers k such that k concatenated with k+4 is a lucky number.

1, 3, 15, 19, 21, 39, 55, 63, 73, 85, 99, 111, 117, 135, 159, 165, 201, 219, 261, 267, 273, 327, 333, 345, 357, 369, 381, 399, 423, 471, 483, 495, 513, 525, 537, 579, 585, 597, 603, 615, 621, 639, 675, 687, 693, 699, 741, 789, 831, 837, 879, 885, 891, 915, 975

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..55.

CROSSREFS

Cf. A000959, A032654.

Sequence in context: A022381 A206367 A039570 * A124877 A111517 A083545

Adjacent sequences: A032641 A032642 A032643 * A032645 A032646 A032647

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, May 15 1998

EXTENSIONS

More terms from Sascha Kurz, Mar 24 2002

Incorrect 681 removed and more terms from Sean A. Irvine, Jun 24 2020

STATUS

approved