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 A112665 Numbers that cannot be expressed as a sum of 2 triangular numbers and a power of 2. 1
 6222, 18081, 22161, 23428, 27342, 29847, 36115, 44137, 47677, 50211, 52534, 56751, 57220, 64008, 70146, 78210, 79632, 81003, 82396, 83538, 84531, 85603, 92374, 92847, 96441, 96873, 97054, 97461, 103572, 103935, 109045, 119685, 121134 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Sequence proposed by Livio Zucca on it.hobby.enigmi. First prime number appearing is 152539. (Cf. A112625) LINKS EXAMPLE 6221 and 6223 are not in the sequence since they can be expressed as 6221 = T(105) + T(32) + 2^7 and 6223 = T(93) + T(56) + 2^8. MATHEMATICA tab = Table[1, {i, 30000}]; T[n_] := (n + n^2)/2; Do[n=T[i]+T[j]+2^k; If[1<=n<=30000, tab[[n]]=0], {i, 0, 244}, {j, 0, i}, {k, 0, 14}]; Position[tab, 1] // Flatten CROSSREFS Cf. A112625. Sequence in context: A172731 A230733 A293355 * A232390 A092726 A291422 Adjacent sequences:  A112662 A112663 A112664 * A112666 A112667 A112668 KEYWORD nonn AUTHOR Giovanni Resta, Jan 12 2006 STATUS approved

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Last modified March 20 17:26 EDT 2018. Contains 300990 sequences. (Running on oeis4.)