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A050600 Recursion counts for summation table A003056 with formula a(y,0) = y, a(y,x) = a((y XOR x),2*(y AND x)) 7
0, 1, 0, 1, 2, 0, 1, 1, 1, 0, 1, 3, 2, 3, 0, 1, 1, 2, 2, 1, 0, 1, 2, 1, 2, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 4, 3, 4, 2, 4, 3, 4, 0, 1, 1, 3, 3, 2, 2, 3, 3, 1, 0, 1, 2, 1, 3, 2, 2, 2, 3, 1, 2, 0, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 0, 1, 3, 2, 3, 1, 3, 2, 3, 1, 3, 2, 3, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 0, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 0 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

Count the summation table A003056 with recursive formula based on identity A+B = (A XOR B)+ 2*(A AND B) given by Schroeppel and then this table gives the number of recursion steps to get the final result.

LINKS

Beeler, M., Gosper, R. W. and Schroeppel, R., HAKMEM, ITEM 23 (Schroeppel)

FORMULA

a(n) -> add1c( (n-((trinv(n)*(trinv(n)-1))/2)), (((trinv(n)-1)*(((1/2)*trinv(n))+1))-n) )

MAPLE

add1c := proc(a, b) option remember; if(0 = b) then RETURN(0); else RETURN(1+add_c(XORnos(a, b), 2*ANDnos(a, b))); fi; end;

CROSSREFS

Column 1: A001511, column 2: A050603, column 3: A050604.

Cf. A050601, A050602, A003056, A048720 (for the Maple implementation of trinv and XORnos, ANDnos)

Sequence in context: A105553 A117165 A024363 * A129691 A117454 A115357

Adjacent sequences:  A050597 A050598 A050599 * A050601 A050602 A050603

KEYWORD

nonn,tabl

AUTHOR

Antti Karttunen Jun 22 1999

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Last modified February 16 12:14 EST 2012. Contains 205908 sequences.