|
| |
|
|
A000015
|
|
Smallest prime power >= n.
|
|
9
| |
|
|
1, 2, 3, 4, 5, 7, 7, 8, 9, 11, 11, 13, 13, 16, 16, 16, 17, 19, 19, 23, 23, 23, 23, 25, 25, 27, 27, 29, 29, 31, 31, 32, 37, 37, 37, 37, 37, 41, 41, 41, 41, 43, 43, 47, 47, 47, 47, 49, 49, 53, 53, 53, 53, 59, 59, 59, 59, 59, 59, 61, 61, 64, 64, 64, 67, 67, 67, 71, 71, 71, 71, 73
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| a(n) = A188666(A110654(n)). [Reinhard Zumkeller, Apr 25 2011]
|
|
|
LINKS
| David W. Wilson, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Prime Power
|
|
|
MATHEMATICA
| Insert[Table[m:=n; While[Not[Length[FactorInteger[m]]==1], m++ ]; m, {n, 2, 100}], 1, 1] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 17 2006
|
|
|
PROG
| (PARI) a(n)=if(n<1, 0, while(matsize(factor(n))[1]>1, n++); n)
(Sage) [next_prime_power(n) for n in xrange(0, 72)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 13 2009]
(Haskell)
a000015 n = a000015_list !! (n-1)
a000015_list = 1 : concat
(zipWith(\pp qq -> replicate (fromInteger (pp - qq)) pp)
(tail a000961_list) a000961_list)
-- Reinhard Zumkeller, Nov 17 2016, Apr 25 2011
|
|
|
CROSSREFS
| Cf. A000961, A031218.
Sequence in context: A076034 A034152 A114707 * A122411 A117174 A022473
Adjacent sequences: A000012 A000013 A000014 * A000016 A000017 A000018
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from Michael Somos, Jul 16 2002
|
| |
|
|
