A213724 Largest natural number x such that x = n + A000120(x), or zero if no such number exists.

1, 3, 0, 5, 7, 0, 0, 9, 11, 0, 13, 15, 0, 0, 0, 17, 19, 0, 21, 23, 0, 0, 25, 27, 0, 29, 31, 0, 0, 0, 0, 33, 35, 0, 37, 39, 0, 0, 41, 43, 0, 45, 47, 0, 0, 0, 49, 51, 0, 53, 55, 0, 0, 57, 59, 0, 61, 63, 0, 0, 0, 0, 0, 65, 67, 0, 69, 71, 0, 0, 73, 75, 0, 77, 79, 0, 0, 0, 81, 83, 0, 85, 87, 0, 0, 89, 91

Offset

0,2

Links

Antti Karttunen, Table of n, a(n) for n = 0..1024

Formula

a(0)=1; and for n>=1, a(n)=0 if A079559(n)=0 (i.e., if A213723(n)=0); otherwise A213723(n)+1.

Prog

(Scheme): (define (A213724 n) (if (zero? n) 1 (let ((v (A213723 n))) (if (zero? v) v (+ 1 v)))))
(Haskell)
a213724 0 = 1
a213724 n = a213723 n + signum (a213723 n)
-- Reinhard Zumkeller, May 01 2015

Crossrefs

One more than A213723 at its nonzero points. a(A005187(n)) = A005408(n). Used for computing A213725-A213727.

Cf. A179016. - M. F. Hasler, Nov 01 2012

Sequence in context: A308123 A308089 A249859 * A350082 A362241 A019915

Adjacent sequences: A213721 A213722 A213723 * A213725 A213726 A213727

Keyword

nonn

Author

Antti Karttunen, Nov 01 2012

Status

approved