A205883 - OEIS

A205883

Length of n-th run of A205600(n).

2, 4, 6, 9, 13, 23, 29, 43, 51, 60, 80, 91, 103, 116, 144, 159, 175, 192, 210, 248, 268, 289, 311, 334, 382, 407, 433, 460, 516, 545, 605, 636, 668, 701, 769, 804, 840, 914, 952, 991, 1031, 1113, 1155, 1198, 1286, 1331, 1377, 1424, 1520, 1569, 1669, 1720, 1824, 1877, 1931, 1986, 2098, 2155, 2271, 2330, 2390, 2512, 2574, 2637, 2701, 2831, 2897, 3031, 3099, 3168, 3238

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

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..71.

Benoit Cloitre, Plot of a(n)/n^2

FORMULA

a(n)=2+sum(k=1,n,A205600(k)*(k-1)). It seems that a(n)=c*n^2+smaller terms with c=0.64...(see graphic provided in the link)

PROG

(PARI) /* program to get the first 100 terms: */ v=[1, 2]; L=[2]; for(n=2, 100, v=if(v[n]-2, concat(v, vector(n-1, i, v[i])), concat(concat(v, vector(n-1, i, v[i])), vector(n-1, i, v[i]))); L=concat(L, [length(v)])); a(n)=L[n]

CROSSREFS

Sequence in context: A280918 A081225 A164140 * A253108 A375109 A198201

Adjacent sequences: A205880 A205881 A205882 * A205884 A205885 A205886

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Jan 10 2013

STATUS

approved