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A318500 Filter sequence combining A305897 and the parity of n. 3
1, 2, 3, 4, 3, 5, 3, 6, 7, 8, 3, 9, 3, 10, 11, 12, 3, 13, 3, 14, 15, 16, 3, 17, 7, 18, 19, 20, 3, 21, 3, 22, 23, 24, 11, 25, 3, 26, 27, 28, 3, 29, 3, 30, 31, 32, 3, 33, 7, 34, 35, 36, 3, 37, 15, 38, 39, 40, 3, 41, 3, 42, 43, 44, 23, 45, 3, 46, 47, 48, 3, 49, 3, 50, 51, 52, 11, 53, 3, 54, 55, 56, 3, 57, 27, 58, 59, 60, 3, 61, 15, 62, 63, 64, 35, 65, 3, 66, 67, 68, 3, 69, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Restricted growth sequence transform of ordered pair [A000035(n), A246277(n)], or equally, of ordered pair [A007814(n), A246277(n)].

For all i, j:

  A305801(i) = A305801(j) => a(i) = a(j) => A305891(i) = A305891(j) => A291761(i) = A291761(j).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..100000

PROG

(PARI)

rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };

A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1, 1])-1); for (i=1, #f~, f[i, 1] = prime(primepi(f[i, 1])-k)); factorback(f)/2);

v318500 = rgs_transform(vector(up_to, n, [(n%2), A246277(n)]));

A318500(n) = v318500[n];

CROSSREFS

Cf. A246277, A291761, A305801, A305891, A305897.

Sequence in context: A322824 A322314 A322022 * A325384 A323371 A319346

Adjacent sequences:  A318497 A318498 A318499 * A318501 A318502 A318503

KEYWORD

nonn

AUTHOR

Antti Karttunen, Sep 24 2018

STATUS

approved

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Last modified October 20 15:29 EDT 2019. Contains 328267 sequences. (Running on oeis4.)