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A073173 Square composite numbers with square subscripts. 0
4, 9, 16, 1225, 6036849, 10909809, 29484900, 326561041, 653058025, 952833424, 10487398464 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(12) > 5*10^11. [From Donovan Johnson, Feb 06 2010]

LINKS

Table of n, a(n) for n=1..11.

FORMULA

Solutions to c[x^2]=y^2: the values of y^2; where c(j)=j-th composite number; See program.

EXAMPLE

composite=1225=35.35=A002808(1024)=c(32.32).

MATHEMATICA

c[x_] := FixedPoint[x+PrimePi[ # ]+1&, x] Do[s=c[n^2]; If[IntegerQ[Sqrt[s]], Print[s]], {n, 1, 1000000}]

CROSSREFS

Cf. A002808, A073171, A073172.

Sequence in context: A082920 A204434 A110979 * A313352 A253601 A313353

Adjacent sequences:  A073170 A073171 A073172 * A073174 A073175 A073176

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 19 2002

EXTENSIONS

a(10)-a(11) from Donovan Johnson, Feb 06 2010

STATUS

approved

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Last modified October 16 06:26 EDT 2019. Contains 328050 sequences. (Running on oeis4.)