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Greatest inverse of A255072; a(n) = largest k such that A255072(k) = n.
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%I #7 Feb 17 2015 00:10:12

%S 0,2,5,6,10,13,14,18,22,26,29,30,34,38,43,46,50,54,58,61,62,66,70,75,

%T 78,85,90,94,98,102,107,110,114,118,122,125,126,130,134,139,142,149,

%U 154,158,165,171,175,181,186,190,194,198,203,206,213,218,222,226,230,235,238,242,246,250,253,254,258

%N Greatest inverse of A255072; a(n) = largest k such that A255072(k) = n.

%H Antti Karttunen, <a href="/A255055/b255055.txt">Table of n, a(n) for n = 0..16143</a>

%F a(0) = 0; for n > 0, a(n) = A255054(n) + a(n-1).

%F Other identities. For all n >= 0:

%F a(n) = A255053(n) + A255054(n) - 1.

%F a(n) = A255056(n) + A255124(n).

%o (Scheme, with _Antti Karttunen_'s IntSeq-library, three different implementations):

%o (definec (A255055 n) (if (zero? n) n (+ (A255054 n) (A255055 (- n 1)))))

%o (define A255055 (COMPOSE -1+ (LEAST-I-WITH-FUN-I-EQ-N 0 0 A255072) 1+)) ;; Slow !

%o (define (A255055 n) (+ (A255053 n) (A255054 n) -1))

%Y Cf. A255053, A255054, A255072.

%Y Analogous sequences: A173601, A219645, A219655.

%K nonn

%O 0,2

%A _Antti Karttunen_, Feb 14 2015