A391852 - OEIS

%I #7 Dec 21 2025 20:02:06

%S 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,18,20,22,24,26,28,30,31,32,

%T 33,36,37,40,41,44,45,48,52,56,60,62,63,64,65,66,67,72,73,74,75,80,82,

%U 88,90,96,97,104,105,112,120,124,126,127,128,129,130,131,132,133,134,135,144,146,148,150,160,161,164,165,176

%N Numbers k such that 17*k = A048720(m, k) for some m, where A048720 is carryless base-2 multiplication.

%C If n is a term, then 2*n is also a term, and vice versa. See A391853 for the odd terms.

%H Antti Karttunen, <a href="/A391852/b391852.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Con#CongruCrossDomain">Index entries for sequences defined by congruent products between domains N and GF(2)[X]</a>.

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>.

%H <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a>.

%F {0 followed by k such that A280500(17*k, k) = m for some m > 0}.

%o (PARI) is_A391852(k) = (!k || (0==lift(Pol(binary(17*k)*Mod(1, 2)) % Pol(binary(k))*Mod(1, 2))));

%Y Cf. A048720, A280500.

%Y Subsequences: A115847 (m=17), A115809 (m=49), A391853 (odd terms).

%K nonn,base

%O 1,3

%A _Antti Karttunen_, Dec 21 2025