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Search: a361478 -id:a361478
     Sort: relevance | references | number | modified | created      Format: long | short | data
Distinct values of A361478, in order of appearance.
+20
2
0, 1, 2, 3, 4, 6, 5, 7, 8, 14, 9, 11, 13, 10, 12, 15, 16, 30, 17, 23, 29, 18, 20, 22, 26, 19, 25, 27, 21, 24, 28, 31, 32, 62, 33, 47, 61, 34, 40, 46, 58, 35, 39, 49, 55, 57, 59, 36, 38, 44, 50, 52, 54, 37, 41, 43, 45, 53, 42, 48, 60, 51, 56, 63, 64, 126, 65
OFFSET
0,3
COMMENTS
This sequence is a permutation of the nonnegative integers with inverse A361482.
FORMULA
a(n) < 2^k iff n < 2^k.
PROG
(PARI) See Links section.
CROSSREFS
Cf. A361478, A361482 (inverse).
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Mar 14 2023
STATUS
approved
a(n) is the least integer whose binary expansion has the same multiset of run-lengths as that of n.
+10
3
0, 1, 2, 3, 4, 5, 4, 7, 8, 9, 10, 9, 12, 9, 8, 15, 16, 17, 18, 19, 18, 21, 18, 17, 24, 19, 18, 19, 24, 17, 16, 31, 32, 33, 34, 35, 36, 37, 36, 35, 34, 37, 42, 37, 36, 37, 34, 33, 48, 35, 36, 51, 36, 37, 36, 35, 56, 35, 34, 35, 48, 33, 32, 63, 64, 65, 66, 67
OFFSET
0,3
FORMULA
a(a(n)) = a(n).
a(n) <= n with equality iff n = 0 or belongs to A175020.
PROG
(PARI) a(n) = { my (r=[]); while (n, my (v=valuation(n+n%2, 2)); n\=2^v; r=concat(v, r)); r=vecsort(r); my (h=0, t=#r+1, v=0); for (k=1, #r, v=(v+k%2)*2^if (k%2, r[h++], r[t--])-k%2; ); return (v); }
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Mar 13 2023
STATUS
approved
a(n) is the greatest integer whose binary expansion has the same multiset of run-lengths as that of n.
+10
3
0, 1, 2, 3, 6, 5, 6, 7, 14, 13, 10, 13, 12, 13, 14, 15, 30, 29, 26, 27, 26, 21, 26, 29, 28, 27, 26, 27, 28, 29, 30, 31, 62, 61, 58, 59, 54, 53, 54, 59, 58, 53, 42, 53, 54, 53, 58, 61, 60, 59, 54, 51, 54, 53, 54, 59, 56, 59, 58, 59, 60, 61, 62, 63, 126, 125
OFFSET
0,3
FORMULA
a(a(n)) = a(n).
a(n) >= n.
PROG
(PARI) a(n) = { my (r=[]); while (n, my (v=valuation(n+n%2, 2)); n\=2^v; r=concat(v, r)); r=vecsort(r); my (h=0, t=#r+1, v=0); for (k=1, #r, v=(v+k%2)*2^if (k%2, r[t--], r[h++])-k%2; ); return (v); }
CROSSREFS
KEYWORD
nonn,look,base
AUTHOR
Rémy Sigrist, Mar 13 2023
STATUS
approved

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