|
| |
|
|
A071184
|
|
a(1)=1, a(n) is the smallest integer > a(n-1) such that the sum of elements of the simple continued fraction for S(n)=1/a(1)+1/a(2)+...+1/a(n) equals n*(n+1)/2 the n-th triangular number.
|
|
0
| |
|
|
1, 2, 8, 10, 60, 75, 131, 195, 988, 1120, 1130, 1232, 1345, 1347, 1953, 2933, 3549, 9956, 13797, 13970, 14586, 14652, 14903, 17166, 19176, 19634, 22584, 24354, 24842, 26488, 29388, 30840, 31409, 34934, 36059, 45149, 49793, 52690, 59413, 61063
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
EXAMPLE
| 1/a(1)+1/a(2)+1/a(3)+1/a(4) = (1+1/2+1/8+1/10) which continued fraction is {1, 1, 2, 1, 1, 1, 3} and 1+1+2+1+1+1+3 = 10 = 4*5/2 the fourth triangular number
|
|
|
PROG
| (PARI) s=1; t=1; for(n=2, 22, s=s+1/t; while(abs(n*(n+1)/2+1-sum(i=1, length(contfrac(s+1/t)), component(contfrac(s+1/t), i)))>0, t++); print1(t, ", "))
|
|
|
CROSSREFS
| Sequence in context: A066707 A107227 A188539 * A174153 A171976 A081231
Adjacent sequences: A071181 A071182 A071183 * A071185 A071186 A071187
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 10 2002
|
|
|
EXTENSIONS
| More terms from Lambert Klasen (lambert.klasen(AT)gmx.de), Dec 18 2004
|
| |
|
|
