A022512 -id:A022512 - cp's OEIS frontend

A022513 Describe previous term from the right (method A - initial term is 9).

9, 19, 1911, 211911, 21192112, 122112192112, 122112191112212211, 2122112231191112212211, 21221122311921132221221112, 12312211321321121921132221221112

Offset: 0

N. J. A. Sloane

Method A = 'frequency' followed by 'digit'-indication.

			E.g., the term after 1911 is obtained by saying "two 1's, one 9, one 1", which gives 211911.

Cf. A005150, A022506, A006711, A022482, A022507-A022512.

More terms from Erich Friedman

A022510 Describe previous term from the right (method A - initial term is 6).

Original entry on oeis.org

6, 16, 1611, 211611, 21162112, 122112162112, 122112161112212211, 2122112231161112212211, 21221122311621132221221112, 12312211321321121621132221221112

Offset: 0

N. J. A. Sloane

Method A = 'frequency' followed by 'digit'-indication.

			E.g., the term after 1611 is obtained by saying "two 1's, one 6, one 1", which gives 211611.

Cf. A022506, A006711, A022482, A022507, A022508, A022509, A022511, A022512, A022513.

a[1]=6; a[n_]:= a[n]= IntegerReverse[ FromDigits[ Flatten[ Replace[ Replace[ Replace[ Split[ IntegerDigits[a[n-1]]], {x_,y_}->{x,Length[{x,y}]},{1}], {x_,y_,z_}->{x,Length[{x,y,z}]},{1}], {x_}->{x,Length[{x}]},{1}]]]];
Array[a,10] (* Ivan N. Ianakiev, Jul 23 2019 *)

from re import split
A022510_list, l = [6], '6'
for _ in range(10):
    l = ''.join(str(len(d))+d[0] for d in split('(0+|1+|2+|3+|4+|5+|6+|7+|8+|9+)',l[::-1]) if d)
    A022510_list.append(int(l)) # Chai Wah Wu, Jan 02 2015

More terms from Erich Friedman

cp's OEIS Frontend

A022513 Describe previous term from the right (method A - initial term is 9).

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