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A342761
Fold a square sheet of paper alternately vertically to the left and horizontally downwards; after each fold, draw a line along each inward crease; after n folds, the resulting graph has a(n) edges.
2
4, 7, 10, 15, 25, 43, 79, 147, 283, 547, 1075, 2115, 4195, 8323, 16579, 33027, 65923, 131587, 262915, 525315, 1050115, 2099203, 4197379, 8392707, 16783363, 33562627, 67121155, 134234115, 268460035, 536903683, 1073790979
OFFSET
0,1
COMMENTS
A342759 is the main sequence for this entry.
FORMULA
Theorem: a(2*t) = 2^(2*t)+3*2^(t-1)+3 for t >= 1; a(2*t+1) = 2^(2*t+1)+2^(t+1)+3 for t >= 0. - N. J. A. Sloane, Apr 26 2021
EXAMPLE
See illustration in Links section.
PROG
(C#) See Links section.
CROSSREFS
Cf. A342759.
It appears that a(n) = A257418(n) + 2 for n >= 2. Hugo Pfoertner, Mar 29 2021 [This is true - N. J. A. Sloane, Apr 26 2021]
Sequence in context: A071408 A137461 A137379 * A096676 A092863 A310707
KEYWORD
nonn
AUTHOR
STATUS
approved