A087052 Lunar triangular numbers: 0+1+2+3+...+n, where + is lunar addition.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 79, 79, 79, 79, 79, 79, 79, 79, 79, 79, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199, 199

Offset

0,3

Comments

Differs from A087121 after 100 terms.

If duplicates are removed we get A051885. - N. J. A. Sloane, Jan 25 2011

Links

Table of n, a(n) for n=0..120.

D. Applegate, C program for lunar arithmetic and number theory [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]

D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]

D. Applegate, M. LeBrun, N. J. A. Sloane, Dismal Arithmetic, J. Int. Seq. 14 (2011) # 11.9.8.

Index entries for sequences related to dismal (or lunar) arithmetic

Maple

(Continuing from A087062) dt := proc(n) local i, t1; t1 := 0; for i from 1 to n do t1 := dadd(t1, i); od: t1; end;

Crossrefs

Cf. A051885.

Sequence in context: A106649 A284030 A087121 * A077557 A332261 A075517

Adjacent sequences: A087049 A087050 A087051 * A087053 A087054 A087055

Keyword

nonn

Author

Marc LeBrun and N. J. A. Sloane, Oct 19 2003

Status

approved