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 A143696 Number of additive cyclic codes over GF(4) of length n that can be generated by one codeword. 1
 4, 10, 24, 46, 72, 260, 400, 766, 1584, 2900, 4104, 19596, 16392, 67240, 139968, 196606, 266256, 1098760, 1048584, 3416604, 10454400, 10506260, 16810000, 83667116, 75497616, 167854100, 415239264, 1275614776, 1073741832, 6341140000, 6179217664, 12884901886 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES W. C. Huffman, Additive cyclic codes over F_4, Advances in Math. Communication, 2 (2008), 309-343. LINKS Table of n, a(n) for n=1..32. FORMULA See A143695 for formula. PROG (PARI) csiz(n, q) = {list = listcreate(n); A = vector(n); for (i=0, n-1, ai = i+1; if (!A[ai], ni = i; nai = ni+1; s = 0; while (! A[nai], A[nai] = 1; s++; ni = lift(Mod(ni*q, n)); nai = ni+1; ); listput(list, s); ); ); return (Vec(list)); } /* algorithm from arXiv:cs/0703129 */ a(n) = {expz = 2^valuation(n, 2); y = n/expz; d = csiz(y, 2); prod(i=1, length(d), 1 + (2^(expz*d[i])-1)*(2^d[i]+1)/(2^d[i]-1)); } \\ Michel Marcus, Mar 06 2013 CROSSREFS Cf. A143695. Sequence in context: A008251 A174934 A083168 * A058514 A182094 A291949 Adjacent sequences: A143693 A143694 A143695 * A143697 A143698 A143699 KEYWORD nonn AUTHOR N. J. A. Sloane, Nov 13 2008, based on email from W. C. Huffman EXTENSIONS More terms from Michel Marcus, Mar 06 2013 STATUS approved

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Last modified June 8 04:57 EDT 2023. Contains 363157 sequences. (Running on oeis4.)