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

Author

Antti Karttunen, Nov 01 2012

Keywords

• nonn

Links

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

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

Programs

Haskell

a213724 0 = 1
a213724 n = a213723 n + signum (a213723 n)
-- Reinhard Zumkeller, May 01 2015

Scheme

(define (A213724 n) (if (zero? n) 1 (let ((v (A213723 n))) (if (zero? v) v (+ 1 v)))))

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.