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A257681
Column index of A257503: If A257685(n) = 0, then a(n) = A257682(n), otherwise a(n) = a(A257685(n)).
9
0, 1, 2, 3, 1, 4, 5, 6, 7, 8, 9, 10, 2, 11, 12, 13, 3, 14, 1, 15, 16, 17, 4, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 5, 43, 44, 45, 6, 46, 47, 48, 49, 50, 51, 52, 7, 53, 54, 55, 8, 56, 9, 57, 58, 59, 10, 60, 2
OFFSET
0,3
COMMENTS
a(0) = 0 by convention, because 0 is not present in arrays A257503 and A257505.
LINKS
FORMULA
If A257685(n) = 0, then a(n) = A257682(n), otherwise a(n) = a(A257685(n)).
PROG
(Scheme, two versions, utilizing memoizing definec-macro)
(definec (A257681 n) (if (zero? (A257685 n)) (A257682 n) (A257681 (A257685 n))))
(definec (A257681 n) (if (or (zero? n) (= 1 (A257680 n))) (A257682 n) (A257681 (A257685 n))))
CROSSREFS
Column index of A257503, row index of A257505.
Cf. also A257679 (gives the other index).
Sequence in context: A117385 A071517 A305433 * A338240 A265755 A341130
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 04 2015
STATUS
approved