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A302848 Permutation of natural numbers: a(1) = 1; for n > 1, a(n) = 1+A064989(A003961(n)-2). 3
1, 2, 3, 6, 4, 12, 5, 10, 20, 18, 8, 42, 7, 30, 15, 74, 14, 72, 11, 60, 48, 32, 9, 86, 44, 26, 75, 90, 24, 102, 16, 240, 21, 22, 19, 212, 23, 62, 80, 92, 38, 158, 13, 58, 168, 40, 27, 320, 66, 70, 59, 150, 35, 368, 84, 160, 110, 56, 54, 312, 34, 108, 111, 720, 45, 192, 39, 122, 78, 228, 68, 662, 36, 50, 33, 112, 87, 134, 17, 328, 416, 114, 47, 300, 128 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

David Newman, et al., New sequences from old, Discussion on SeqFan-mailing list, January 2018.

Index entries for sequences that are permutations of the natural numbers

Index entries for sequences computed from indices in prime factorization

FORMULA

a(1) = 1; for n > 1, a(n) = 1+A064989(A003961(n)-2).

a(1) = 1; for n > 1, a(n) = 1+A064216(A048673(n)-1).

PROG

(PARI)

A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From A003961

A064989(n) = {my(f); f = factor(n); if((n>1 && f[1, 1]==2), f[1, 2] = 0); for (i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f)};

A302848(n) = if(1==n, n, 1+A064989(A003961(n)-2));

CROSSREFS

Cf. A302847 (inverse).

Cf. A003961, A048673, A064216, A064989, A302850.

Sequence in context: A104663 A246429 A305325 * A046202 A225642 A273317

Adjacent sequences:  A302845 A302846 A302847 * A302849 A302850 A302851

KEYWORD

nonn

AUTHOR

Antti Karttunen, Apr 26 2018

STATUS

approved

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Last modified May 9 03:34 EDT 2021. Contains 343685 sequences. (Running on oeis4.)