A392220 A modified Sisyphus function: a(n) = concatenation of (number of digits in n) (number of odd digits in n) (number of even digits in n).

101, 110, 101, 110, 101, 110, 101, 110, 101, 110, 211, 220, 211, 220, 211, 220, 211, 220, 211, 220, 202, 211, 202, 211, 202, 211, 202, 211, 202, 211, 211, 220, 211, 220, 211, 220, 211, 220, 211, 220, 202, 211, 202, 211, 202, 211, 202, 211, 202, 211, 211, 220, 211, 220, 211

Offset

0,1

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

Example

a(12345) = 532, since 12345 has 5 total digits, 3 odd digits and 2 even digits.

Mathematica

A392220[n_] := FromDigits[Flatten[IntegerDigits[{Length[#], Count[#, _?OddQ], Count[#, _?EvenQ]}]]] & [IntegerDigits[n]];
Array[A392220, 100, 0]

Prog

(Python)
def a(n): # T0E
    s = str(n)
    e = sum(1 for c in s if c in "02468")
    return int(str(len(s)) + str(len(s)-e) + str(e))
print([a(n) for n in range(55)]) # Michael S. Branicky, Jan 13 2026

Crossrefs

Cf. other concatenation variants (where E, O and T = number of even, odd and total digits, respectively): A073053 (EOT), A171797 (TEO), A308003 (ETO), A308005 (OTE), A392477 (OET).

Cf. A055642, A196563, A196564.

Sequence in context: A107219 A366106 A140799 * A086918 A259300 A383306

Adjacent sequences: A392217 A392218 A392219 * A392221 A392222 A392223

Keyword

nonn,base,easy

Author

Paolo Xausa, Jan 03 2026

Status

approved