A239722 Numbers that end in (..., 384, 384, 384, ...) under the rule: next term = product of the last four digits in the sequence so far.

12, 13, 14, 17, 19, 21, 24, 28, 38, 42, 61, 62, 68, 69, 112, 113, 114, 117, 119, 121, 122, 123, 126, 128, 129, 131, 133, 134, 136, 137, 142, 143, 144, 148, 162, 163, 173, 177, 179, 182, 184, 192, 197, 199, 211, 212, 217, 218, 221, 224, 228, 231, 242, 244, 249, 267, 268, 271, 274, 278, 281, 282, 284, 287, 294, 299, 311, 312, 321

Offset

1,1

Comments

Additional rule: If there are fewer than k=4 digits in the sequence so far, then it is "extended to the left" with the first digit (i.e., that digit is repeated as often as necessary).

Apart from the trivial cycles (0) (cf. A239616) and (1) and the cycle (384) considered here, the rule also allows the "constant" cycle (175), cf. A239721.

Links

Table of n, a(n) for n=1..69.

Prog

(PARI) is_A239722(n) = A238984(99, n, 4)==384 \\ The "99" here should be large enough to reach the cycle (384), for small initial values n. It might be necessary to increase this value in other cases.

Crossrefs

Cf. A238984, A239419, A239616, A239721.

Sequence in context: A209725 A045879 A257073 * A112655 A308919 A048026

Adjacent sequences: A239719 A239720 A239721 * A239723 A239724 A239725

Keyword

nonn,base

Author

M. F. Hasler, Aug 01 2014

Status

approved