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A111440 Squares of the form semiprime(n) + prime(n). 2
9, 25, 64, 81, 400, 576, 1024, 1296, 2304, 2704, 4096, 7225, 7744, 10816, 14884, 15376, 19044, 20736, 22500, 25600, 26244, 28900, 33124, 35344, 39601, 41616, 46656, 47961, 48400, 52900, 55225, 89401, 91204, 96100, 99856, 114921, 136900 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
The first 3 semiprimes are {4,6,9} and the first 3 primes are {2,3,5}. The second term in each are {6,3} whose sum is 9, a square. - _Robert G. Wilson v_
MATHEMATICA
sp = Select[ Range[10^5], Plus @@ Last /@ FactorInteger@ # == 2 &]; s = Select[ Range@Length@sp, IntegerQ[ Sqrt[sp[[ # ]] + Prime@# ]] &]; sp[[s]] + Prime[s]; (* _Robert G. Wilson v_ *)
CROSSREFS
Sequence in context: A147353 A049740 A147405 * A077118 A242116 A209530
KEYWORD
nonn
AUTHOR
_Giovanni Teofilatto_, Nov 14 2005
EXTENSIONS
More terms from _Robert G. Wilson v_, Nov 18 2005
STATUS
approved

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Last modified May 26 07:46 EDT 2024. Contains 372807 sequences. (Running on oeis4.)