OFFSET
1,1
COMMENTS
Previous name was: 143*7n.
Property of 143*7n shown by Ghersi (see References):
a(n) = n00n for n from 1 to 9;
a(n) = n0n for n from 10 to 99;
a(n) = nn for n from 100 to 999.
REFERENCES
I. Ghersi, Matematica dilettevole e curiosa, Hoepli (1967), p. 138
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
G.f.: 1001*x/(1-x)^2. - Vincenzo Librandi, Feb 26 2012 [corrected by Georg Fischer, May 10 2019]
a(n) = 2*a(n-1) - a(n-2). - Vincenzo Librandi, Feb 26 2012
MATHEMATICA
Table[1001 n, {n, 1, 40}] (* Bruno Berselli, Mar 30 2016 *)
PROG
(PARI) for(n=1, 40, print1(1001*n", ")); \\ Vincenzo Librandi, Feb 26 2012
(Magma) [1001*n: n in [1..40]]; // Bruno Berselli, Mar 30 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 02 2009
EXTENSIONS
Name changed by Michel Marcus, Mar 30 2016
STATUS
approved