OFFSET
1,1
EXAMPLE
205427 = P(234) + P(287) = P(201) + P(311) = P(166) + P(331) = P(56) + P(366) = P(49) + P(367), where P(n) is the n-th pentagonal number (A000326).
PROG
(PARI) is(k) = sum(i=1, sqrt(1+12*k)\6, sqrt(1+24*k+12*i-36*i*i)%6==5) == 5; \\ Jinyuan Wang, Mar 06 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Olivier Gérard, Mar 05 2020
EXTENSIONS
More terms from Jinyuan Wang, Mar 06 2020
STATUS
approved