

A056234


Form an array with 3 rows: row 1 begins with 1; all rows are increasing; each entry is sum of 2 entries above it; each number appears at most once; smallest unused number is appended to first row if possible. Sequence gives numbers not used.


8



5, 24, 29, 42, 72, 90, 93, 112, 120, 125, 138, 158, 172, 175, 192, 197, 200, 205, 208, 213, 218, 230, 235, 264, 282, 285, 302, 305, 310, 321, 324, 329, 333, 364, 372, 375, 378, 386, 416, 430, 439, 452, 455, 477, 496, 504, 509, 522, 542, 556
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OFFSET

1,1


LINKS

Zak Seidov and Reinhard Zumkeller, Table of n, a(n) for n = 1..10000


EXAMPLE

Array begins
1 2 4 7 8 10 12 ...
.3 6 11 15 18 ...
. 9 17 26 33 ...


PROG

(Haskell)
a056234 n = a056234_list !! (n1)
a056234_list = notUsed 1 a056231_list a056232_list a056233_list where
notUsed x us'@(u:us) vs'@(v:vs) ws'@(w:ws)
 x == u = notUsed (x + 1) us vs' ws'
 x == v = notUsed (x + 1) us' vs ws'
 x == w = notUsed (x + 1) us' vs' ws
 otherwise = x : notUsed (x + 1) us' vs' ws'
 Reinhard Zumkeller, Nov 07 2011


CROSSREFS

Cf. A056231, A056232, A056233. See also A057153, A052474, A057154, A056230.
Sequence in context: A333633 A222355 A335352 * A030766 A063143 A006145
Adjacent sequences: A056231 A056232 A056233 * A056235 A056236 A056237


KEYWORD

nonn,nice,easy


AUTHOR

N. J. A. Sloane, E. M. Rains, Aug 22 2000


STATUS

approved



