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A049967
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a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 1.
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3
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1, 3, 1, 8, 21, 37, 79, 187, 524, 864, 1733, 3495, 7140, 14957, 32545, 76552, 214699, 352849, 705703, 1411435, 2823020, 5646717, 11296065, 22603592, 45268779, 90813855, 182686296, 369607874, 756172623, 1580555509, 3439905037
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OFFSET
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1,2
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LINKS
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PROG
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(PARI) lista(nn) = { nn = max(nn, 3); my(va = vector(nn)); va[1] = 1; va[2] = 3; va[3] = 1; my(sa = vecsum(va)); for (n=4, nn, va[n] = sa + va[2*(n - 1 - 2^logint(n-2, 2))]; sa += va[n]; ); va; } \\ Petros Hadjicostas, May 03 2020
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CROSSREFS
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Cf. A049918 (similar, but with minus a(m/2)), A049919 (similar, but with minus a(m)), A049966 (similar, but with plus a(m/2)).
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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