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A285810 Primes equal to a centered pentagonal number plus 1. 4
2, 7, 17, 107, 227, 277, 457, 857, 1627, 3517, 4517, 5407, 9767, 11057, 13877, 15017, 16607, 20477, 23767, 26267, 27827, 35107, 37517, 41927, 42577, 50767, 53657, 58907, 62017, 68477, 79657, 83267, 86027, 93607, 98507, 110777, 113957, 128257, 137477, 145807 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Colin Barker, Table of n, a(n) for n = 1..1000

PROG

(PARI) cpg(m, n) = m*n*(n-1)/2+1 \\ n-th centered m-gonal number

maxk=600; L=List(); for(k=1, maxk, if(isprime(p=cpg(5, k) + 1), listput(L, p))); Vec(L)

CROSSREFS

Cf. A000040, A005891, A285809, A285811, A285812.

Sequence in context: A283754 A122382 A025554 * A028888 A082627 A160617

Adjacent sequences:  A285807 A285808 A285809 * A285811 A285812 A285813

KEYWORD

nonn

AUTHOR

Colin Barker, Apr 27 2017

STATUS

approved

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Last modified October 24 00:33 EDT 2021. Contains 348217 sequences. (Running on oeis4.)