login
A232087
Second-order base-10 grafting integers.
2
0, 1, 8, 77, 98, 99, 100, 764, 765, 5711, 5736, 9797, 9998, 9999, 10000, 76394, 77327, 997997, 999998, 999999, 1000000, 2798254, 7639321, 8053139, 25225733, 42808341, 57359313, 60755907, 62996069, 99979997, 99999998, 99999999, 100000000, 127016654
OFFSET
1,3
COMMENTS
Second-order base-10 grafting integers are integers that, when expressed in base 10, will appear in their own square root before or directly after the decimal point (ignoring leading 0's and including trailing 0's).
All numbers of the form 10^2n, 10^2n - 1, and 10^2n - 2, n >= 1, are terms.
All numbers of the form (10^n-3)*(10^n+1), n > 0, are terms.
REFERENCES
Robert Tanniru, A short note introducing Grafting Numbers and their connection to Catalan Numbers, J. Comb. Math. and Comb. Computing, 95 (2015), 309-312.
EXAMPLE
sqrt(764) = 27.64054992...
sqrt(77327) = 278.0773273749...
sqrt(1000000) = 1000.000...
PROG
(PARI)
/* Uses PARI functions provided in link
* Sample run uses a = [0, 11], b=10, p=2, direct=FALSE */
GetAllGIs(0, 11, 10, 2, 0)
CROSSREFS
Cf. A074841 (subsequence).
Sequence in context: A231286 A251927 A024281 * A105429 A225348 A091686
KEYWORD
nonn,base
AUTHOR
Robert Tanniru, Nov 17 2013
STATUS
approved