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A038044 Shifts left under transform T where Ta is a DCONV a. 6
1, 1, 2, 4, 9, 18, 40, 80, 168, 340, 698, 1396, 2844, 5688, 11456, 22948, 46072, 92144, 184696, 369392, 739536, 1479232, 2959860, 5919720, 11842696, 23685473, 47376634, 94753940, 189519576, 379039152, 758102900, 1516205800 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

LINKS

N. J. A. Sloane, Transforms

FORMULA

a(1)=1, a(n+1)=sum(d|n, a(d)*a(n/d)); a(prime(k)+1)=2*a(prime(k)); a(n) is asymptotic to c*2^n where c=0.353030198... - Benoit Cloitre, Aug 29 2004

MAPLE

with(numtheory); EIGENbyDIRCONV := proc(upto_n) local n, a, j, i, s, m; a := [1]; for i from 1 to upto_n do s := 0; m := convert(divisors(i), set); n := nops(m); for j from 1 to n do s := s+(a[m[j]]*a[m[(n-j)+1]]); od; a := [op(a), s]; od; RETURN(a); end;

CROSSREFS

Positions of odd terms are given by A003095. Other self-convolved sequences: A000108, A007460 - A007464, A025192, A061922, A062177.

Sequence in context: A018000 A036610 A193201 * A189911 A026732 A171003

Adjacent sequences:  A038041 A038042 A038043 * A038045 A038046 A038047

KEYWORD

nonn,eigen

AUTHOR

Christian G. Bower (bowerc(AT)usa.net)

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Last modified February 17 04:58 EST 2012. Contains 205985 sequences.