|
| |
|
|
A055872
|
|
a(n) and floor[a(n)/8] are both squares; i.e. squares which remain squares when written in base 8 and last digit is removed.
|
|
14
| |
|
|
0, 1, 4, 9, 36, 289, 1156, 9801, 39204, 332929, 1331716, 11309769, 45239076, 384199201, 1536796804, 13051463049, 52205852196, 443365544449, 1773462177796, 15061377048201, 60245508192804
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
COMMENTS
| For the first 3 terms which have only 1 digit in base 8, removing this digit is meant to yield 0.
Base-8 analogue of A055792 (base 2), A055793 (base 3), A055808 (base 4), A055812 (base 5), A055851 (base 6), A055859 (base 7), A204503 (base 9) and A023110 (base 10). - M. F. Hasler, Jan 15 2012
|
|
|
FORMULA
| a(n)=A204514(n)^2. - M. F. Hasler, Jan 15 2012
|
|
|
EXAMPLE
| a(5) = 289 because 289 = 17^2 = 441 base 8 and 44 base 8 = 36 = 6^2
|
|
|
PROG
| (PARI) b=8; for(n=1, 200, issquare(n^2\b) & print1(n^2, ", ")) \\ - M. F. Hasler, Jan 15 2012
|
|
|
CROSSREFS
| Cf. A023110.
Sequence in context: A176830 A077211 A073977 * A066924 A149146 A149147
Adjacent sequences: A055869 A055870 A055871 * A055873 A055874 A055875
|
|
|
KEYWORD
| base,nonn
|
|
|
AUTHOR
| Henry Bottomley (se16(AT)btinternet.com), Jul 14 2000
|
|
|
EXTENSIONS
| More terms added and offset changed to 1 by M. F. Hasler, Jan 15 2012
|
| |
|
|
