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A038394 Concatenate first n primes in reverse order. 5
2, 32, 532, 7532, 117532, 13117532, 1713117532, 191713117532, 23191713117532, 2923191713117532, 312923191713117532, 37312923191713117532, 4137312923191713117532 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

F. Smarandache, Sequences of Numbers Involved in Unsolved Problems, Hexis, Phoenix, 2006.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..300

Mihaly Bencze [Beneze] and L. Tutescu, editors, Some Notions and Questions in Number Theory, Vol. II.

M. Fleuren, Smarandache Back Concatenated Primes.

F. Smarandache, Sequences of Numbers Involved in Unsolved Problems.

MAPLE

P:=proc(i) local a, n; a:=2; print(a); for n from 2 by 1 to i do a:=a+ithprime(n)*10^floor(evalf((log10(a)+1), 100)); print(a); od; end: P(100); # Paolo P. Lava, Jan 21 2009

MATHEMATICA

Join[{s = 2}, Table[s = FromDigits[Flatten[IntegerDigits[{Prime[n], s}]]], {n, 2, 13}]] (* Jayanta Basu, Jul 14 2013 *)

PROG

(Haskell)

a038394 n = a038394_list !! (n-1)

a038394_list = f "" a000040_list where

   f xs (q:qs) = (read ys :: Integer) : f ys qs

     where ys = show q ++ xs

-- Reinhard Zumkeller, Mar 03 2014

CROSSREFS

Cf. A000040, A019518.

Sequence in context: A010045 A052151 A092844 * A068110 A304860 A198599

Adjacent sequences:  A038391 A038392 A038393 * A038395 A038396 A038397

KEYWORD

nonn,base

AUTHOR

M. I. Petrescu (mipetrescu(AT)yahoo.com)

EXTENSIONS

Offset corrected by Reinhard Zumkeller, Mar 03 2014

STATUS

approved

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Last modified September 16 08:52 EDT 2019. Contains 327092 sequences. (Running on oeis4.)