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A061205
a(n) = n times R(n) where R(n) (A004086) is the digit reversal of n.
16
0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 10, 121, 252, 403, 574, 765, 976, 1207, 1458, 1729, 40, 252, 484, 736, 1008, 1300, 1612, 1944, 2296, 2668, 90, 403, 736, 1089, 1462, 1855, 2268, 2701, 3154, 3627, 160, 574, 1008, 1462, 1936, 2430, 2944, 3478, 4032, 4606
OFFSET
0,3
COMMENTS
Every third term is divisible by 9, no other term is divisible by 3. - Alonso del Arte, Mar 04 2013
LINKS
Harry J. Smith and Indranil Ghosh, Table of n, a(n) for n = 0..10000 (first 1001 terms from Harry J. Smith)
EXAMPLE
a(10) = 10 = 10 * 01.
a(11) = 121 = 11 * 11.
a(12) = 252 = 12 * 21.
a(13) = 403 = 13 * 31.
MATHEMATICA
#*FromDigits[Reverse[IntegerDigits[#]]] &/@Range[0, 49] (* Ant King, Jan 07 2012 *)
#*IntegerReverse[#]& /@ Range[0, 49] (* Jean-François Alcover, Oct 27 2019 *)
PROG
(PARI) { for (n=0, 1000, x=n; r=0; while (x>0, d=x-10*(x\10); x\=10; r=r*10 + d); write("b061205.txt", n, " ", n*r) ) } \\ Harry J. Smith, Jul 18 2009
(PARI) rev(k) = subst(Polrev(digits(k)), x, 10);
a(n) = n*rev(n); \\ Michel Marcus, Feb 14 2015
(PARI) a(n) = n*fromdigits(Vecrev(digits(n))); \\ Michel Marcus, May 28 2018
(Haskell)
a061205 n = a004086 n * n
-- Reinhard Zumkeller, Apr 10 2012, Apr 29 2011
(Python)
def A061205(n):
return n*A004086(n) # Indranil Ghosh, Jan 09 2017
CROSSREFS
Cf. A004086, A203924 (triple repetitions).
Sequence in context: A361203 A057147 A213630 * A290934 A048387 A035121
KEYWORD
nonn,base,look
AUTHOR
Amarnath Murthy, Apr 21 2001
EXTENSIONS
Corrected and extended by Patrick De Geest, Jun 04 2001
STATUS
approved