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A216208 a(1) = 11. a(n) is obtained by filling the space between neighboring entries by the sum of the first two entries of a(n-1). 1
11, 121, 13231, 143424341, 15453545254535451, 165646563656465626564656365646561, 17675767476757673767576747675767276757674767576737675767476757671 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Definition of "entry": Call each digit of a(1) and each inserted sum an entry.

(1) Philosophy.  Sequence expresses the nesting pattern of hierarchical higher-order vagueness (formal description in Bobzien 2013, 17-20; informal description e.g. in Shapiro 2005, 147-8) (2) Biology.  At least the first five numbers of the sequence are manifested in various biological structures,  so in vessel arrangement in Microcosmus helleri;  in the pereional appendages of Augustidontus seriatus, in the rip structure (“Berippung”) of pecten (velopecten) Vewzprimiensis Bittn.(formal description in Salson 2010, 115).

REFERENCES

S. Bobzien, Higher-order vagueness and borderline nestings - a persistent confusion, Analytic Philosophy 54 (2013), 1-49.

M. Salson, Structures d'indexation compressées et dynamiques pour le texte (doctoral dissertation, bioinformatics) Université de Rouen 2010.

LINKS

Table of n, a(n) for n=1..7.

FORMULA

a(1) = 11. a(n) is obtained by filling the space between neighboring entries by the sum of the first two entries of a(n-1).

EXAMPLE

a(2) = 121; for a(3), in 1-2-1 the two (-) are replaced by 1+2 = 3 hence a(3) = 13231.

MATHEMATICA

a[1]="11"; a[n_] := a[n] = StringInsert[a[n-1], ToString@n, 1 + Range[2^(n-1)]]; Table[a[n], {n, 9}] (* Giovanni Resta, Mar 12 2013 *)

CROSSREFS

Sequence in context: A088760 A080486 A082776 * A110398 A176595 A067218

Adjacent sequences:  A216205 A216206 A216207 * A216209 A216210 A216211

KEYWORD

base,easy,nonn

AUTHOR

Susanne Bobzien, Mar 12 2013

STATUS

approved

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Last modified August 17 22:59 EDT 2019. Contains 326059 sequences. (Running on oeis4.)