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A210455 Characteristic function of pseudoperfect (or semiperfect) numbers. 7
0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

a(A005835(n)) = 1 and a(A136447(n)) = 0.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Semiperfect Number

Wikipedia, Semiperfect number

Index entries for characteristic functions

PROG

(Haskell)

a210455 n = fromEnum $ p (a027751_row n) n where

   p ks m = m == 0 || not (null ks) && head ks <= m &&

            (p (tail ks) (m - head ks) || p (tail ks) m)

CROSSREFS

Cf. A027751.

Sequence in context: A093958 A044936 A133944 * A294936 A296210 A094912

Adjacent sequences:  A210452 A210453 A210454 * A210456 A210457 A210458

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jan 21 2013

STATUS

approved

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Last modified February 20 07:41 EST 2020. Contains 332069 sequences. (Running on oeis4.)