A191748 -id:A191748 - cp's OEIS frontend

A191747 Concatenation of row entries of the n X n identity matrices.

1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1

Offset: 1

L. Edson Jeffery, Jun 27 2011

The sequence of all n for which a(n)=1 is A191748 = {1,2,5,6,10,14,...}.

Flatten[Table[Array[KroneckerDelta, {n, n}], {n, 1, 6}]] (* Geoffrey Critzer, Dec 11 2011 *)

for(n=1,9,for(a=1,n,for(b=1,n,print1(a==b", ")))) \\ Charles R Greathouse IV, Jun 29 2011

A338819 The entries in the rows of the n X n identity matrix, multiplied by the size of the matrix (n).

Original entry on oeis.org

1, 2, 0, 0, 2, 3, 0, 0, 0, 3, 0, 0, 0, 3, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 5, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 5, 6, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 6, 7, 0

Offset: 1

Julia Zimmerman, Nov 10 2020

			For every identity matrix of size n starting with n=1, append n*(each entry of each row of the matrix), e.g., n=1 -> 1, n=2 -> 2,0,0,2, so the first 5 terms of the sequence are 1,2,0,0,2.

Cf. A191747 (with 1's), A191748 (locations of nonzero terms), A056520 (start location of each matrix).

import numpy as np
def n_id_sequence(iterations):
    sequence = []
    for i in range(1,iterations+1):
        matrix = i*(np.identity(i))
        for row in matrix:
            for entry in row:
                sequence.append(int(entry))
    return sequence

cp's OEIS Frontend

A191747 Concatenation of row entries of the n X n identity matrices.

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A338819 The entries in the rows of the n X n identity matrix, multiplied by the size of the matrix (n).

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