ever and

ever and

again/anon
Now and then; occasionally.
See also: and, ever
References in classic literature ?
He had perceived some movement perhaps; but at any rate he stood, and ever and again slashed at the fallen body.
The two Germans at the machine heard his voice going ever and again amidst the clamour of the waters.
Ever and again, to pass the time, he would cover one or other of them with his gun.
Their punk-pop is still as fresh as ever and it's obvious they are having as much fun as the crowd.