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 A051638 a(n) = sum_{k=0..n} (C(n,k) mod 3). 8
 1, 2, 4, 2, 4, 8, 4, 8, 13, 2, 4, 8, 4, 8, 16, 8, 16, 26, 4, 8, 13, 8, 16, 26, 13, 26, 40, 2, 4, 8, 4, 8, 16, 8, 16, 26, 4, 8, 16, 8, 16, 32, 16, 32, 52, 8, 16, 26, 16, 32, 52, 26, 52, 80, 4, 8, 13, 8, 16, 26, 13, 26, 40, 8, 16, 26, 16, 32, 52, 26, 52, 80, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Row sums of the triangle in A083093. - Reinhard Zumkeller, Jul 11 2013 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..6561=3^8 Michael Gilleland, Some Self-Similar Integer Sequences A. Granville, Binomials modulo a prime FORMULA Write n in base 3; if the representation contains r 1's and s 2's then a(n) = 2^{r-1} * (3^(s+1) - 1) = 1/2 * (3*A006047(n) - 2^(A062756(n))). - Robin Chapman, Ahmed Fares (ahmedfares(AT)my-deja.com) and others, Jul 16 2001 MATHEMATICA Table[2^(DigitCount[n, 3, 1]-1) (3^(DigitCount[n, 3, 2]+1)-1), {n, 0, 80}] (* Harvey P. Dale, Jun 20 2019 *) PROG (Haskell) a051638 = sum . a083093_row  -- Reinhard Zumkeller, Jul 11 2013 CROSSREFS Cf. A001316. Sequence in context: A318768 A166242 A143107 * A286580 A286598 A286557 Adjacent sequences:  A051635 A051636 A051637 * A051639 A051640 A051641 KEYWORD nonn AUTHOR STATUS approved

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Last modified April 10 22:31 EDT 2021. Contains 342856 sequences. (Running on oeis4.)