A376793 Numbers k such that k and k+1 are both in A376616.

1, 1424, 2484, 4304, 4655, 6223, 10624, 13824, 20624, 22784, 29448, 33424, 33984, 36944, 41535, 43263, 45184, 45324, 65744, 66199, 68624, 69632, 70784, 74304, 74627, 99584, 103103, 103424, 105720, 114704, 120680, 139904, 147636, 164224, 166144, 192576, 199968

Offset: 1

Author

Amiram Eldar, Oct 04 2024

Keywords

• nonn
• base

Examples

			1424 is a term since both 1424 and 1425 are in A376616: 1424/A000120(1424) = 356 and 356/A000120(356) = 89 are integers, and 1425/A000120(1425) = 285 and 285/A000120(285) = 57 are integers.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Subsequence of A330931 and A376616.

Subsequences: A376794, A376795.

Cf. A000120.

Programs

Mathematica

q[k_] := q[k] = Module[{w = DigitCount[k, 2, 1]}, Divisible[k, w] && Divisible[k/w, DigitCount[k/w, 2, 1]]]; Select[Range[20000], q[#] && q[#+1] &]

PARI

is1(k) = {my(w = hammingweight(k)); !(k % w) && !((k/w) % hammingweight(k/w));}
lista(kmax) = {my(q1 = is1(1), q2); for(k = 2, kmax, q2 = is1(k); if(q1 && q2, print1(k-1, ", ")); q1 = q2);}