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 A083228 A Jacobsthal related sequence. 2
 1, 3, 21, 341, 10923, 699051, 89478485, 22906492245, 11728124029611, 12009599006321323, 24595658764946068821, 100743818301219097892181, 825293359523586849932749483, 13521606402434446949298167524011 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..55 FORMULA a(n) = A001045(binomial(n+2, 2)) = 2^binomial(n+2, 2)/3 - (-1)^binomial(n+2, 2)/3. PROG (Magma) [2^Binomial(n+2, 2)/3-(-1)^Binomial(n+2, 2)/3: n in [0..15]]; // Vincenzo Librandi, Jun 29 2011 (PARI) a(n)=2^binomial(n+2, 2)\/3 \\ Charles R Greathouse IV, Jun 29 2011 CROSSREFS Cf. A000217. Sequence in context: A240936 A342245 A332928 * A052445 A351130 A186271 Adjacent sequences: A083225 A083226 A083227 * A083229 A083230 A083231 KEYWORD easy,nonn AUTHOR Paul Barry, Apr 23 2003 STATUS approved

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Last modified September 12 20:35 EDT 2024. Contains 375854 sequences. (Running on oeis4.)