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A087462 Generalized mod 3 multiplicative Jacobsthal sequence. 3
1, 1, 1, 8, 5, 11, 64, 43, 85, 512, 341, 683, 4096, 2731, 5461, 32768, 21845, 43691, 262144, 174763, 349525, 2097152, 1398101, 2796203, 16777216, 11184811, 22369621, 134217728, 89478485, 178956971, 1073741824, 715827883, 1431655765 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

2^n=A087462(n)+A087463(n)+A087464(n) provides a decomposition of Pascal's triangle. Multiplicative analogue of A078008.

FORMULA

a(n)=sum{k=0..n, if (mod(nk, 3)=0, 1, 0)C(n, k)}; a(n)=2^n-2/3(1-cos(2pi*n/3))(A001045(n)+2*A001045(n-1)+0^n).

CROSSREFS

Cf. A001045.

Sequence in context: A070473 A154210 A198996 * A168204 A193681 A199806

Adjacent sequences:  A087459 A087460 A087461 * A087463 A087464 A087465

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Sep 08 2003

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Last modified February 14 23:16 EST 2012. Contains 205687 sequences.