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A002442 Squares written in base 9.
(Formerly M3377 N1361)
1
1, 4, 10, 17, 27, 40, 54, 71, 100, 121, 144, 170, 207, 237, 270, 314, 351, 400, 441, 484, 540, 587, 647, 710, 764, 831, 1000, 1061, 1134, 1210, 1277, 1357, 1440, 1524, 1611, 1700, 1781, 1874, 2070, 2167, 2267, 2370, 2474, 2581, 2700, 2811, 3024, 3140, 3257 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
REFERENCES
GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See pages 108 and 300.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
V. Thébault, Les Récréations Mathématiques. Gauthier-Villars, Paris, 1952, p. 98.
LINKS
FORMULA
a(n) = A007095(A000290(n)). - Jason Kimberley, Dec 13 2012
MAPLE
f:= proc(n) local L, i;
L:= convert(n^2, base, 9);
add(L[i]*10^(i-1), i=1..nops(L))
end proc:
map(f, [$1..100]); # Robert Israel, Aug 12 2018
MATHEMATICA
Table[FromDigits[IntegerDigits[n^2, 9]], {n, 1, 100}] (* Stefan Steinerberger, Apr 11 2006 *)
PROG
(Magma) [Seqint(Intseq(n^2, 9)): n in [1..60]]; // Vincenzo Librandi, Oct 16 2015
(PARI) a(n) = fromdigits(digits(n^2, 9)); \\ Michel Marcus, Aug 13 2018
CROSSREFS
Sequence in context: A294249 A138105 A213398 * A350143 A301253 A341772
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
More terms from Stefan Steinerberger, Apr 11 2006
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)