|
%I #34 Mar 08 2023 09:35:43
%S 0,1,4,9,6,5,6,9,4,1,100,121,144,169,186,105,126,149,164,181,400,441,
%T 484,429,466,405,446,489,424,461,900,961,924,989,946,905,966,929,984,
%U 941,600,681,664,649,626,605,686,669,644,621,500,501,504,509,506,505
%N Carryless squares n X n base 10.
%H Seiichi Manyama, <a href="/A059729/b059729.txt">Table of n, a(n) for n = 0..9999</a>
%H David Applegate, Marc LeBrun and N. J. A. Sloane, <a href="http://neilsloane.com/doc/carry1.pdf">Carryless Arithmetic (I): The Mod 10 Version</a>.
%H <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a>
%e a(87) is carryless sum of (6)400, (5)60, (5)60 and (4)9, i.e., 400+20+9 = 429.
%o (Python)
%o def A059729(n):
%o s = [int(d) for d in str(n)]
%o l = len(s)
%o t = [0]*(2*l-1)
%o for i in range(l):
%o for j in range(l):
%o t[i+j] = (t[i+j] + s[i]*s[j]) % 10
%o return int("".join(str(d) for d in t)) # _Chai Wah Wu_, Jun 29 2020
%o (PARI) a(n) = fromdigits(Vec(Pol(digits(n))^2)%10) \\ _Ruud H.G. van Tol_, Dec 07 2022
%Y Cf. A004520, A059692, A169889, A169963.
%Y See A087019 (lunar squares) for another version.
%K base,easy,nonn,look
%O 0,3
%A _Henry Bottomley_, Feb 20 2001
|
