

A298301


The first of three consecutive heptagonal numbers the sum of which is equal to the sum of three consecutive primes.


4



7, 874, 7209, 15484, 16687, 23863, 68641, 98704, 122877, 239785, 373842, 455182, 498852, 523723, 601966, 652036, 769230, 777573, 1003939, 1019844, 1121245, 1189215, 1203049, 1420159, 1484946, 1594804, 1606807, 1687977, 1804975, 2292973, 2533612, 3012363
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OFFSET

1,1


LINKS



EXAMPLE

7 is in the sequence because 7+18+34 (consecutive hexagonal numbers) = 59 = 17+19+23 (consecutive primes).


PROG

(PARI) L=List(); forprime(p=2, 2000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(120*t519, &sq) && (sq21)%30==0, u=(sq21)\30; listput(L, (5*u^23*u)/2))); Vec(L)


CROSSREFS

Cf. A000040, A000566, A054643, A298073, A298168, A298169, A298222, A298223, A298250, A298251, A298272, A298273, A298302.


KEYWORD

nonn


AUTHOR



STATUS

approved



