[go: up one dir, main page]

login
A110414
n! concatenated with n divided by n.
1
11, 11, 21, 61, 241, 1201, 7201, 50401, 403201, 36288001, 362880001, 3991680001, 47900160001, 622702080001, 8717829120001, 130767436800001, 2092278988800001, 35568742809600001, 640237370572800001
OFFSET
1,1
FORMULA
(n-1)! followed by a 1.
EXAMPLE
a(14) = 622702080001: 14! concatenated with 14 is 8717829120014 and 87178291200/14 = 622702080001.
MAPLE
c:=proc(x, y) local s: s:=proc(m) nops(convert(m, base, 10)) end: x*10^s(y)+y: end: a:=n->c(n!, n)/n: seq(a(n), n=1..22); # c yields the concatenation of two positive integers # Emeric Deutsch, Aug 07 2005
MATHEMATICA
Table[(n!*10^IntegerLength[n]+n)/n, {n, 20}] (* Harvey P. Dale, Sep 10 2016 *)
PROG
(PARI) a(n) = fromdigits(concat(digits(n!), digits(n)))/n; \\ Michel Marcus, Aug 18 2019
CROSSREFS
Cf. A110415.
Sequence in context: A167130 A299781 A168459 * A040111 A003887 A138844
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Aug 01 2005
EXTENSIONS
More terms from Emeric Deutsch and Erich Friedman, Aug 07 2005
STATUS
approved