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A306014
Numbers k such that A055228(k)^2 - A055228(k) is a multiple of k, where A055228(k) is ceiling(sqrt(k!)).
1
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 16, 28, 29, 30, 42, 46, 50, 52, 99, 134, 148, 165, 205, 245, 249, 315, 390, 441, 461, 525, 560, 763, 962, 1596, 1666, 1716, 1847, 1854, 1860, 3515, 4501, 5179, 6850, 7345, 7867, 8940, 9491, 9523, 15688, 19988, 23574, 23956
OFFSET
1,2
REFERENCES
Hazewinkel, Michiel, ed. (2001) [1994], Gamma Function, Encyclopedia of Mathematics, Springer Science+Business Media B.V. / Kluwer Academic Publishers, ISBN 978-1-55608-010-4
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..89 (all terms up to 10^6, n = 1..70 from Jon E. Schoenfield)
EXAMPLE
For n=6, ceiling(sqrt(6!))=27, (ceiling(sqrt(6!))^2=729, and 729-27 = 702, which is a multiple of 6.
MATHEMATICA
Select[Range[4600], Divisible[Ceiling[Sqrt[#!]]^2-Ceiling[Sqrt[#!]], #]&] (* Harvey P. Dale, Mar 02 2023 *)
PROG
(PARI) default(realprecision, 10^5); for(n=1, 10^4, if( Mod( ceil(sqrt(n!)) - ceil(sqrt(n!))^2 , n) == 0, print1(n, ", "))); \\ Joerg Arndt, Jun 17 2018
CROSSREFS
Sequence in context: A134932 A134933 A136040 * A271838 A194846 A194057
KEYWORD
nonn
AUTHOR
Ivan Stoykov, Jun 17 2018
EXTENSIONS
Terms > 99 from Joerg Arndt, Jun 17 2018
STATUS
approved