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A238256 A060308 begins with one 2, one 3, one 5, two 7's, one 11, two 13's, i.e., d(n) = 1, 1, 1, 2, 1, 2, 1, 2, 3, 1,... times the primes (A000040). a(n) uses this distribution with noncomposites (A008578). 1
1, 2, 3, 5, 5, 7, 11, 11, 13, 17, 17, 19, 19, 19, 23, 29, 29, 29, 31, 31, 37, 41, 41, 43, 43, 43, 47, 47, 47, 53, 59, 59, 59, 61, 61, 67, 71, 71, 71, 73, 73, 79, 79, 79, 83, 83, 83, 83, 89, 89, 97, 101, 101, 103, 107, 107, 109, 109, 109, 109, 109, 109, 109 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Paul Curtz, Table of n, a(n) for n = 1..63

FORMULA

Conjecture: a(n) is the greatest noncomposite (A008578) dividing A238691(n-1).

PROG

(PARI) lista(nn) = {nn = nn\2; v = vector(nn, i, precprime(2*i)); vnc = concat(1, vector(nn, i, prime(i))); nv = vector(1, i, vnc[i]); ivnc = 1; for (i=2, #v, if (v[i] == v[i-1], nv = concat(nv, nv[#nv]), ivnc++; nv = concat(nv, vnc[ivnc])); ); for (i=1, #nv, print1(nv[i], ", ")); } \\ Michel Marcus, Mar 20 2014

CROSSREFS

Cf. A224911.

Sequence in context: A084754 A120724 A117530 * A239277 A302445 A094749

Adjacent sequences:  A238253 A238254 A238255 * A238257 A238258 A238259

KEYWORD

nonn

AUTHOR

Paul Curtz, Mar 10 2014

STATUS

approved

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Last modified May 8 21:32 EDT 2021. Contains 343668 sequences. (Running on oeis4.)