A260716 a(n) = number of iterations of A234742 needed when starting from A091209(n) before a fixed point is reached.

6, 4, 55, 141, 2, 2, 4, 5, 3, 4, 3, 14, 2, 1, 4, 3, 1, 18, 6, 3, 17, 36, 1, 10, 13, 1, 10, 2, 2, 86, 27, 7, 4, 50, 1, 4, 6, 4, 3, 13, 7, 3, 1, 207, 2, 7, 10, 10, 128, 7, 2, 4, 2, 9, 20, 2, 15, 24, 3, 10, 64, 7, 4, 4, 1, 4, 15, 8, 4, 1, 45, 3, 2, 1, 1, 2, 6, 28, 1, 2, 11, 1, 3, 14, 13, 3, 11, 12, 4, 28, 3, 7, 55, 40, 9, 4, 51, 5, 2, 6, 1, 2, 1, 15, 1

Offset

1,1

Comments

It is not known whether the sequence is well-defined for all values. For example, does a(144) have a finite value? Cf. the sequence A260441, starting iteration from 1361 = A091209(144).

Links

Antti Karttunen, Table of n, a(n) for n = 1..143

Formula

a(n) = A260712(A091209(n)).

Prog

(PARI)
allocatemem((2^29));
v091209 = [5, 17, 23, 29, 43, 53, 71, 79, 83, 89, 101, 107, 113, 127, 139, 149, 151, 163, 173, 179, 181, 197, 199, 223, 227, 233, 251, 257, 263, 269, 271, 277, 281, 293, 307, 311, 317, 331, 337, 347, 349, 353, 359, 367, 373, 383, 389, 401, 409, 421, 431, 439, 443, 449, 457, 461, 467, 479, 491, 503, 509, 521, 523, 541, 547, 569, 571, 577, 593, 599, 619, 641, 643, 653, 659, 673, 683, 691, 709, 727, 733, 739, 743, 751, 773, 797, 809, 811, 821, 823, 829, 839, 853, 857, 863, 881, 887, 907, 919, 937, 941, 947, 977, 983, 991, 997, 1009, 1013, 1021, 1031, 1049, 1061, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1129, 1151, 1171, 1181, 1187, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1283, 1289, 1297, 1301, 1303, 1307, 1319, 1321, 1327];
A091209(n) = v091209[n];
A234742(n) = factorback(subst(lift(factor(Mod(1, 2)*Pol(binary(n)))), x, 2)); \\ After M. F. Hasler's Feb 18 2014 code.
A260712(n) = {my(prev=-1, i=-1); until((n==prev), prev = n; n = A234742(n); i++); return(i); }
A260716(n) = A260712(A091209(n));
for(n=1, 143, write("b260716.txt", n, " ", A260716(n)));
(Scheme) (define (A260716 n) (A260712 (A091209 n)))

Crossrefs

Cf. A091209, A234742, A260712, A260713, A260441.

Sequence in context: A333813 A327370 A375789 * A112521 A192350 A308900

Adjacent sequences: A260713 A260714 A260715 * A260717 A260718 A260719

Keyword

nonn

Author

Antti Karttunen, Aug 04 2015

Status

approved