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 A227364 a(n) = 1 + 2*3 + 4*5*6 + 7*8*9*10 + ... + ...*n  (see Example lines). 3
 0, 1, 3, 7, 11, 27, 127, 134, 183, 631, 5167, 5178, 5299, 6883, 29191, 365527, 365543, 365799, 370423, 458551, 2226007, 39435607, 39435629, 39436113, 39447751, 39739207, 47329207, 252562807, 6006997207, 6006997236, 6006998077, 6007024177, 6007860247, 6035477527, 6975328087 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS EXAMPLE a(5) = 1 + 2*3 + 4*5 = 27; a(6) = 1 + 2*3 + 4*5*6 = 127; a(7) = 1 + 2*3 + 4*5*6 + 7 = 134. PROG (Python) for n in range(55):   sum = 0   i = k = 1   while i<=n:     product = 1     for x in range(k):       product *= i       i += 1       if i>n: break     sum += product     k += 1   print str(sum)+', ', CROSSREFS Cf. A227363, A227365-A227367. Sequence in context: A001645 A103798 A093361 * A051202 A211674 A035095 Adjacent sequences:  A227361 A227362 A227363 * A227365 A227366 A227367 KEYWORD nonn AUTHOR Alex Ratushnyak, Jul 07 2013 STATUS approved

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Last modified December 12 10:19 EST 2019. Contains 329953 sequences. (Running on oeis4.)