You may not be able to find the exact patten you've used in the past, but this is a very common pattern type. I've seen dozens in both hand and machine knitting. In fact, I'd wager you can find something extremely similart - maybe even identical - for free online, and I also think you could find the pattern for free in the yarn department of the store. (those little displays all along the yarn aisle) They have some cute patterns there. I dont' care for the acryllic yarn, but some of the patterns are cute.
I created one myself too, that specializes in decreases (increases, really, but they are crossed) several stitches in from the edge of the raglan, for a cabled effect. If I can still find it (It was printed on an old dot-matrix printer, and the paper is yellowed beyond belief), I'll scan it and send it to you. There is no copyright problem because I created it myself. But mine was for women. You could reverse the button/buttonhole band and make it for a man, too. But I didn't figure the stitches for a child.
(EDIT: a cursory search yielded this pattern - for any size and any weight yarn - you plug in your measurements, gauge and multiply & go http://www.woolworks.org/patterns/raglan.html