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 A224923 Sum_{i=0..n} Sum_{j=0..n} (i XOR j), where XOR is the binary logical exclusive-or operator. 4
 0, 2, 12, 24, 68, 114, 168, 224, 408, 594, 788, 984, 1212, 1442, 1680, 1920, 2672, 3426, 4188, 4952, 5748, 6546, 7352, 8160, 9096, 10034, 10980, 11928, 12908, 13890, 14880, 15872, 18912, 21954, 25004, 28056, 31140, 34226, 37320, 40416, 43640, 46866, 50100, 53336, 56604 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..1023 PROG (Python) for n in range(99): ....s = 0 ....for i in range(n+1): ........for j in range(n+1): ............s += i ^ j ....print s, # Alex Ratushnyak, Apr 19 2013 (Python) # O(log(n)) version, whereas program above is O(n^2) def countPots2Until(n): ....nbPots = {1:n>>1} ....lftMask = ~3 ....rgtMask = 1 ....digit = 2 ....while True: ........lft = (n & lftMask) >> 1 ........rgt = n & rgtMask ........nbDigs = lft ........if n & digit: ............nbDigs |= rgt ........if nbDigs == 0: ............return nbPots ........nbPots[digit] = nbDigs ........rgtMask |= digit ........digit <<= 1 ........lftMask = lftMask ^ digit def sumXorSquare(n): ...."""Returns sum(i^j for i, j <= n)""" ....n += 1 ....nbPots = countPots2Until(n) ....return 2 * sum(pot * freq * (n - freq) for pot, freq in nbPots.items()) print([sumXorSquare(n) for n in range(100)])  # Miguel Garcia Diaz, Nov 19 2014 CROSSREFS Cf. A004125, A222423, A224915, A224924. Sequence in context: A146567 A176679 A278407 * A247086 A121119 A226899 Adjacent sequences:  A224920 A224921 A224922 * A224924 A224925 A224926 KEYWORD nonn,base AUTHOR Alex Ratushnyak, Apr 19 2013 STATUS approved

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Last modified June 15 17:43 EDT 2019. Contains 324142 sequences. (Running on oeis4.)