The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A061395

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A061395

Let p be the largest prime factor of n; if p is the k-th prime then set a(n) = k; a(1) = 0 by convention.
(history; published version)

#70 by Robert C. Lyons at Tue Dec 31 14:01:19 EST 2024

STATUS

reviewed

approved

#69 by Michel Marcus at Tue Dec 31 13:42:57 EST 2024

STATUS

proposed

reviewed

#68 by Andrew Howroyd at Tue Dec 31 13:35:24 EST 2024

STATUS

editing

proposed

#67 by Andrew Howroyd at Tue Dec 31 13:18:51 EST 2024

PROG

(PARI) { for (n=1, 1000, if (n==1, a=0, f=factor(n)~; p=f[1, length(f)]; a=primepi(p)); write("b061395.txt", n, " ", a) ) } \\ Harry J. Smith, Jul 22 2009

STATUS

approved

editing

Discussion

Tue Dec 31

13:35

Andrew Howroyd: Essentially same as PARI below

#66 by Alois P. Heinz at Mon Feb 20 08:54:38 EST 2023

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proposed

approved

#65 by Michel Marcus at Mon Feb 20 08:18:27 EST 2023

STATUS

editing

proposed

#64 by Michel Marcus at Mon Feb 20 08:18:16 EST 2023

COMMENTS

Records occur at the primes. - Robert G. Wilson v, Dec 30 2007.

STATUS

approved

editing

Discussion

Mon Feb 20

08:18

Michel Marcus: no period here

#63 by Michael De Vlieger at Mon Nov 14 13:35:47 EST 2022

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proposed

approved

#62 by Michel Marcus at Mon Nov 14 12:55:01 EST 2022

STATUS

editing

proposed

#61 by Michel Marcus at Mon Nov 14 12:44:18 EST 2022

PROG

(PARI) a(n) = if (n==1, 0, primepi(vecmax(factor(n)[, 1]))); \\ Michel Marcus, Nov 14 2022

STATUS

approved

editing