

A013322


Golombtype sequence over triangular numbers.


2



1, 3, 3, 3, 6, 6, 6, 10, 10, 10, 15, 15, 15, 15, 15, 15, 21, 21, 21, 21, 21, 21, 28, 28, 28, 28, 28, 28, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66
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OFFSET

1,2


COMMENTS

All terms are triangular numbers; a(n) is length of nth run.
It is understood that a(n) is taken to be the smallest number >= a(n1) which is compatible with the description.
The apparent idempotence, a(a(n))=a(n), holds while n<191 and breaks after that.  Ivan Neretin, Apr 03 2015


LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000


MAPLE

A:= 1, 3, 3, 3:
for n from 4 to 30 do
t:= n*(n1)/2;
A:= A, t$A[n1]
od:
A; # Robert Israel, Apr 03 2015


MATHEMATICA

a = {1, 3, 3, 3}; Do[a = Join[a, Array[i(i+1)/2&, a[[i]]]], {i, 3, 11}]; a (* Ivan Neretin, Apr 03 2015 *)


CROSSREFS

Cf. A001462.
Sequence in context: A057944 A281258 A080607 * A211534 A219816 A177821
Adjacent sequences: A013319 A013320 A013321 * A013323 A013324 A013325


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane


STATUS

approved



