A361875 Integers of the form k*2^m + 1 where 0 < k <= m and k is odd.
3, 5, 9, 17, 25, 33, 49, 65, 97, 129, 161, 193, 257, 321, 385, 513, 641, 769, 897, 1025, 1281, 1537, 1793, 2049, 2561, 3073, 3585, 4097, 4609, 5121, 6145, 7169, 8193, 9217, 10241, 12289, 14337, 16385, 18433, 20481, 22529, 24577, 28673, 32769, 36865, 40961, 45057, 49153, 57345, 65537, 73729, 81921
Offset: 1
Examples
641 = 5*2^7 + 1 is a term because 0 < 5 <= 7 and 5 is odd.
Crossrefs
Cf. A361180 (prime terms).
Programs
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Maple
# Maple program (due to David A. Corneth) aList := proc(upto) local i, j, R: R := {}: for i from 1 to ilog2(upto) do for j from 1 to min(i, floor(upto/2^i)) do R := `union`(R, {j*2^i+1}): od: od: R: end: aList(10^12);
Comments