This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A153814 #28 Apr 10 2025 17:37:47
%S A153814 1001,2002,3003,4004,5005,6006,7007,8008,9009,10010,11011,12012,13013,
%T A153814 14014,15015,16016,17017,18018,19019,20020,21021,22022,23023,24024,
%U A153814 25025,26026,27027,28028,29029,30030,31031,32032,33033,34034,35035,36036,37037,38038
%N A153814 a(n) = 1001*n.
%C A153814 Previous name was: 143*7n.
%C A153814 Property of 143*7n shown by Ghersi (see References):
%C A153814 a(n) = n00n for n from 1 to 9;
%C A153814 a(n) = n0n for n from 10 to 99;
%C A153814 a(n) = nn for n from 100 to 999.
%D A153814 I. Ghersi, Matematica dilettevole e curiosa, Hoepli (1967), p. 138
%H A153814 Vincenzo Librandi, <a href="/A153814/b153814.txt">Table of n, a(n) for n = 1..1000</a>
%H A153814 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A153814 From _Vincenzo Librandi_, Feb 26 2012: (Start)
%F A153814 G.f.: 1001*x/(1-x)^2.
%F A153814 a(n) = 2*a(n-1) - a(n-2). (End) [G.f. corrected by _Georg Fischer_, May 10 2019]
%F A153814 E.g.f.: 1001*x*exp(x). - _Elmo R. Oliveira_, Apr 10 2025
%t A153814 Table[1001 n, {n, 1, 40}] (* _Bruno Berselli_, Mar 30 2016 *)
%o A153814 (PARI) for(n=1, 40, print1(1001*n", ")); \\ _Vincenzo Librandi_, Feb 26 2012
%o A153814 (Magma) [1001*n: n in [1..40]]; // _Bruno Berselli_, Mar 30 2016
%Y A153814 Cf. A018768.
%K A153814 nonn,easy
%O A153814 1,1
%A A153814 _Vincenzo Librandi_, Jan 02 2009
%E A153814 Name changed by _Michel Marcus_, Mar 30 2016