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A217929 Number of sequences of n 2's and 3's with curling number 2,  which have the form XY^2 with Y = 2, and which are robust. 2
0, 0, 1, 2, 4, 7, 16, 30, 63, 122, 251, 495, 1003, 1990, 4012, 7992, 16043, 32024, 64173, 128226, 256692, 513131, 1026765, 2053034, 4107060, 8213109, 16428221, 32854454, 65712883, 131421763, 262851530, 525695069, 1051406116 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Let S be a sequence of n 2's and 3's with curling number 2 and which has the form XY^2 with Y = 2. S is robust if no proper suffix of S^3 has curling number > 2.

LINKS

Table of n, a(n) for n=1..33.

Index entries for sequences related to curling numbers

CROSSREFS

Cf. A217832, A217930.

Sequence in context: A026731 A026764 A027230 * A320465 A259544 A294376

Adjacent sequences:  A217926 A217927 A217928 * A217930 A217931 A217932

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Oct 15 2012

STATUS

approved

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Last modified January 22 09:52 EST 2019. Contains 319363 sequences. (Running on oeis4.)