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A191992 Concatenation of n and the n-th composite number. 2
14, 26, 38, 49, 510, 612, 714, 815, 916, 1018, 1120, 1221, 1322, 1424, 1525, 1626, 1727, 1828, 1930, 2032, 2133, 2234, 2335, 2436, 2538, 2639, 2740, 2842, 2944, 3045, 3146, 3248, 3349, 3450, 3551, 3652, 3754, 3855, 3956, 4057, 4158, 4260, 4362, 4463, 4564, 4665, 4766, 4868, 4969, 5070, 5172, 5274, 5375, 5476 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

MATHEMATICA

Module[{upto=55, cmps, len}, cmps=Select[Range[10*upto], CompositeQ]; len= Min[ Length[ cmps], upto]; #[[1]]*10^IntegerLength[#[[2]]]+#[[2]]&/@ Thread[{ Range[ len], Take[cmps, len]}]] (* Harvey P. Dale, Dec 05 2016 *)

PROG

(PARI) n=0; for(k=4, 1e3, if(isprime(k), k++); print1(n++k", ")) \\ Charles R Greathouse IV, Jun 21 2011

CROSSREFS

Cf. A045532, the prime analog of this sequence.

Cf. A246801, primes in this sequence.

Sequence in context: A235688 A176274 A240227 * A082773 A242395 A112772

Adjacent sequences:  A191989 A191990 A191991 * A191993 A191994 A191995

KEYWORD

nonn,base,changed

AUTHOR

Kausthub Gudipati, Jun 20 2011

STATUS

approved

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Last modified December 8 02:07 EST 2016. Contains 278902 sequences.