A358511 Positions of ones in A342991.

1, 2, 4, 5, 7, 12, 14, 15, 16, 17, 18, 19, 21, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 56, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 90, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 111, 132, 134

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Mathematica

A358511[i_]:=Module[{pos=-1}, Flatten[Array[{pos+=2, pos+=4#+1, Range[pos+=2, pos+=4#+1]}&, i, 0]]]; (* i-th iteration adds 4*i terms *)
A358511[10]

Prog

(PARI)
A358511(i)=my(a=List(), pos=-1, r); for(j=0, i-1, r=j<<2; listput(a, [pos+=2, pos+=r+1]); pos++; listput(a, vector(r+2, x, x+pos)); pos+=r+2); concat(Vec(a)); \\ i-th iteration adds 4*i terms
A358511[10]
(Python)
def A358511(i): # i-th iteration adds 4*i terms
    a, pos = [], 0
    for j in range(0, i):
        a.extend([pos := pos + 1, pos := pos + (j<<2) + 1])
        a.extend(range(pos := pos + 2, pos := pos + (j<<2) + 2))
    return a
print(A358511(10))

Crossrefs

Cf. A342991, A358510 (complement).

Sequence in context: A039674 A090649 A154686 * A165196 A007062 A121817

Adjacent sequences: A358508 A358509 A358510 * A358512 A358513 A358514

Keyword

nonn,easy

Author

Paolo Xausa, Nov 20 2022

Status

approved