|
| |
|
|
A115439
|
|
Numbers n such that the square of n is the concatenation of two numbers k and k+5.
|
|
11
| |
|
|
4, 7, 45, 56, 38163, 61838, 83618, 346980, 653021, 950051, 8647555, 9534265, 8167822283, 9007920992, 9209900792, 9950000501, 4737445289221, 4990568257187, 5009431742814, 5262554710780, 8373808925585
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| All numbers of the form f(n)=9(n).5.0(2n).5.0(n-1).1 where n>0 are in the sequence because if k(n)=9(n).0(n).25.0(n-1).9(n).6 then f(n)^2=k(n).(k(n)+5). For example f(2)=9950000501; k(2)=9900250996 and f(2)^2=9950000501^2=9900250996.9900251001 =k(2).(k(2)+5). - Farideh Firoozbakht (mymontain(AT)yahoo.com), Nov 26 2006
|
|
|
EXAMPLE
| 38163^2 = 14564_14569.
|
|
|
CROSSREFS
| Cf. A030467, A106497, A115428, A115427, A115438, A115440, A115441, A115442, A115443, A115444, A115445, A115446, A115447.
Sequence in context: A093102 A199404 A139030 * A192168 A094609 A049191
Adjacent sequences: A115436 A115437 A115438 * A115440 A115441 A115442
|
|
|
KEYWORD
| base,nonn
|
|
|
AUTHOR
| Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 24 2006
|
| |
|
|
