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A050236 Indices of consecutive squares palindromic primes; x such that x^2 + (x+1)^2 is palindromic and prime. 3
1, 9, 12, 1262 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
No other terms < 20000000000. - Patrick De Geest, Aug 15 1999
LINKS
Carlos Rivera, Puzzle 14. Pal-Primes and sum of powers, The Prime Puzzles & Problems Connection.
Eric Weisstein's World of Mathematics, Palindromic Prime
MATHEMATICA
Flatten[Position[Total/@Partition[Range[1300]^2, 2, 1], _?(PrimeQ[#] && IntegerDigits[#]==Reverse[IntegerDigits[#]]&)]] (* Harvey P. Dale, Dec 09 2014 *)
PROG
(PARI) isok(m) = my(p=m^2+(m+1)^2); if (isprime(p), my(d=digits(p)); (d == Vecrev(d))); \\ Michel Marcus, Jan 05 2019
CROSSREFS
Cf. A050239.
Intersection of A027861 and A027571.
Sequence in context: A188001 A273614 A281224 * A193995 A070607 A340490
KEYWORD
nonn,nice,hard,base
AUTHOR
STATUS
approved

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Last modified April 18 18:58 EDT 2024. Contains 371781 sequences. (Running on oeis4.)