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A257956
Row sums of A232642, when seen as a triangle read by rows.
3
1, 6, 24, 74, 220, 626, 1754, 4860, 13390, 36762, 100728, 275666, 753898, 2060924, 5632550, 15391650, 42056008, 114907626, 313947186, 857741852, 2343430222
OFFSET
1,2
COMMENTS
a(n) <= A166060(n).
FORMULA
Conjectures from Colin Barker, May 29 2015: (Start)
a(n) = 3*a(n-1)+a(n-2)-4*a(n-3)-2*a(n-4) for n>4.
G.f.: x*(5*x^2+3*x+1) / ((x^2+x-1)*(2*x^2+2*x-1)).
(End)
PROG
(Haskell)
a257956 = sum . a232642_row
CROSSREFS
Sequence in context: A290132 A297713 A225383 * A341364 A180437 A276179
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 14 2015
STATUS
approved