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

Author

Antti Karttunen, Aug 04 2015

Keywords

• nonn

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

Crossrefs

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

Programs

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)))

Formula

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