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A132925 2^n - 1 + n*(n-1)/2. +0
3
1, 4, 10, 21, 41, 78, 148, 283, 547, 1068, 2102, 4161, 8269, 16474, 32872, 65655, 131207, 262296, 524458, 1048765, 2097361, 4194534, 8388860, 16777491, 33554731, 67109188, 134218078, 268435833, 536871317, 1073742258, 2147484112 (list; graph; listen)
OFFSET

1,2

COMMENT

Row sums of triangle A132924. n-th Mersenne number + (n-1)-th triangular number.

Partial sums of A006127 [Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Oct 16 2009]

FORMULA

Binomial transform of [1, 3, 3, 2, 2, 2, 2,...].

a(n) = A000225(n) + A000217(n-1). [Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Oct 16 2009]

EXAMPLE

a(4) = 21 = sum of row 4 terms of triangle A132924: (4 + 4 + 5 + 8).

a(4) = 21 = (1, 3, 3, 1) dot (1, 3, 3, 2) = (1 + 9 + 9 + 2).

MAPLE

with(combinat):a:=n->sum(stirling2(k, 2)+fibonacci(2, k), k=0..n): seq(a(n), n=1..30); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 05 2008

A132925 := proc(n) 2^n-1+n*(n-1)/2 ; end proc; [R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 23 2009]

CROSSREFS

Cf. A132924.

Sequence in context: A144897 A001891 A121497 this_sequence A166553 A053643 A111927

Adjacent sequences: A132922 A132923 A132924 this_sequence A132926 A132927 A132928

KEYWORD

nonn

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Sep 05 2007

EXTENSIONS

More terms from Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Oct 16 2009

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Last modified November 25 08:46 EST 2009. Contains 167481 sequences.


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