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 A219835 Number of terms of 2^j + 3^k <= 10^n. 2
 7, 29, 64, 118, 181, 254, 354, 453, 565, 708, 878, 1033, 1224, 1403, 1594, 1828, 2046, 2274, 2553, 2808, 3139, 3467, 3765, 4073, 4443, 4779, 5124, 5537, 5911, 6294, 6690, 7266, 7693, 8129, 8650, 9114, 9588, 10153, 10654, 11167, 11776, 12449, 13005, 13662, 14243 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS As n-> infinity, a(n) -> log_2(n)*log_3(n). LINKS Zak Seidov, Table of n, a(n) for n = 1..1000 MATHEMATICA Join[{7, 29}, Table[m = 10^x; -4 + Floor [ Log[3, m ]] + Sum[Floor @ Log[2, m - 3^i], {i, 0, Log[3, m]}], {x, 3, 100}]] PROG (Python) def a(n):     s, pow3, lim = set(), 1, 10**n     while pow3 < lim:         for j in range((lim-pow3).bit_length()):             s.add(2**j + pow3)         pow3 *= 3     return len(s) print([a(n) for n in range(1, 46)]) # Michael S. Branicky, Jul 29 2021 CROSSREFS Cf. A004050 (numbers of the form 2^j + 3^k). Sequence in context: A031380 A005698 A080185 * A041621 A022272 A185438 Adjacent sequences:  A219832 A219833 A219834 * A219836 A219837 A219838 KEYWORD nonn AUTHOR Zak Seidov, Nov 29 2012 STATUS approved

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Last modified August 17 03:11 EDT 2022. Contains 356180 sequences. (Running on oeis4.)